Mitochondrial Replacement Therapy

MITOCHONDRIAL REPLACEMENT THERAPY:

FACTORS IN DECISION-MAKING

A Thesis Presented to the Faculty of California State University, Stanislaus

In Partial Fulfillment of the Requirements for the Degree of Master of Science in Genetic Counseling

By Suzanna Tai May 2020 CERTIFICATION OF APPROVAL

MITOCHONDRIAL REPLACEMENT THERAPY:

FACTORS IN DECISION-MAKING

by Suzanna Tai

Signed Certification of Approval page is on file with the University Library

Sign by email______June 1st 2020______Dr. Janey Youngblom, PhD Date Professor of Genetics California State University Stanislaus

Sign by email______June 1st 2020______Kara Weisiger, MS, CGC Date Genetic Counselor Kaiser Permanente Oakland

Sign by email______June 1st 2020______Kelsey McClelland, MS, CGC Date Genetic Counselor Myriad Women’s Health

ACKNOWLEDGEMENTS

I would like to thank the mitochondrial disease community for their participation and support of this research. The vulnerability in sharing your stories to help other families affected with mitochondrial disease is appreciated and needed.

This study was funded by California State University Stanislaus’ College of

Science Biology Research (BRC) and Student Engagement in Research, Scholarship, and Creative Activity (SERSCA) grants.

A sincere thank you to my committee members Kara Weisiger, Kelsey

McClelland, and Janey Youngblom for their insight and support during the research and writing process. I would like to express my appreciation to Rebecca Lee for her expertise in qualitative research and analysis. Thank you to the California State

University Class of 2020 for the support and encouragement along the way.

TABLE OF CONTENTS PAGE

Acknowledgements ...... iv

List of Tables ...... vii

List of Figures...... viii

Abstract ...... ix

CHAPTER I. Introduction ...... 1

II. Materials and Methods ...... 8

Recruitment ...... 8 Development of Materials ...... 9 Data Collection - Quantitative ...... 10 Data Analysis – Quantitative ...... 10 Data Collection – Qualitative ...... 11 Data Analysis – Qualitative ...... 11

III. Results...... 13

Demographics ...... 13 Knowledge About Mitochondrial Conditions and MRT ...... 15 Personal Experiences ...... 19 Motivations ...... 23 Reservations ...... 27

IV. Discussion ...... 35

Influence of Personal Experiences ...... 35 Motivations for Own Family ...... 35 Broader Benefits ...... 37 Reservations with Process of MRT ...... 38 Societal Concerns ...... 41 Recommendations ...... 44 Limitations...... 46 Future Research ...... 47

V. Conclusion ...... 48

References ...... 49

Appendices

A. Participant Letter ...... 57 B. Survey ...... 59 C. Interview Guide...... 70

LIST OF TABLES

TABLE PAGE

1. Demographic Information ...... 13

2. Descriptive Statistical Information on Participants’ Overall Self-rated Knowledge

Score on the Survey ...... 16

3. Descriptive Statistical Information on Participants’ Average Self-rated

Knowledge Score on the General Mitochondrial Topics and Average Self-rated

Knowledge Score on MRT Alone ...... 17

4. Dependent Samples Statistical T-test Determining if Difference Between General

Mitochondrial Knowledge and MRT-specific Knowledge is Significant ...... 18

vii

LIST OF FIGURES

FIGURE PAGE

1. Likert Scale ...... 16

2. Bar Graph ...... 18

viii ABSTRACT

Females affected with mitochondrial disease originating from the maternally inherited mitochondrial DNA (mtDNA) have struggled in the past with the decision to have biological children who are at risk of developing symptoms of mitochondrial disease.

Mitochondrial replacement therapy (MRT) was developed as a reliable means of preventing the transmission of mtDNA-based mitochondrial disease to offspring.

MRT involves using a donor oocyte as a source of healthy mitochondria, while preserving the intended parent’s genetic link to their child. We examined the decision-making factors that those impacted by mtDNA-based disease would consider about MRT. A quantitative survey was utilized to collect demographic information and gauge participant knowledge about mitochondrial disease and MRT.

Qualitative interviews were conducted with eleven people impacted by mitochondrial disease. Participants, although supportive of MRT, were aware of potential risks it may introduce. Included in the findings were the influences of the patient’s personal experiences, motivations to pursue MRT, reservations about MRT, and recommendations surrounding the optimization of MRT from the patient perspective.

As MRT is not currently legal or available in the US, it is important to take patient voices into consideration when implementing policies and introducing new therapies into the clinic setting.

CHAPTER I

INTRODUCTION

Mitochondrial diseases can be devastating for families, with symptoms that can be debilitating or even result in death. Mitochondrial function is critical for energy production in cells. The organs that are typically most affected are those which rely heavily on this energy production - the heart, brain, muscles, and lungs.

However, any organ can be affected by mitochondrial disease. Mitochondrial encephalopathy lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy and ragged red fiber disease (MERRF), and Leber’s hereditary optic neuropathy (LHON) are three examples of mitochondrial disorders due to mitochondrial DNA (mtDNA) variants.

Mitochondrial disease can arise from variants within the nuclear DNA

(nDNA) or mitochondrial DNA (mtDNA). Although the rate of mitochondrial disease is estimated to be 1 in 4000 in the US population (U.S. National Library of Medicine,

2016), 1 in 200 people are estimated to carry a pathogenic mutation in their mtDNA

(Elliott et al., 2008). Though these diseases all share their origins in mtDNA, they fall on a wide spectrum of disease severity. LHON is typically considered to be a mtDNA-based mitochondrial disease of lesser severity. Those affected with LHON will present with symptoms in their twenties and thirties, and about 50% of males and

90% of females with a mutation will never show symptoms (Yu-Wai-Man and

Chinnery, 2000). In contrast, 65-76% of those who are affected with MELAS will present with symptoms at or before age 20, though penetrance is more variable (El-

Hattab et al., 2001).

Mitochondrial disease caused by mtDNA variants has several unique factors that contribute to variable disease presentation: including maternal inheritance, heteroplasmy and the bottleneck effect. The mitochondria are passed through the maternal line only, part of the oocyte before fertilization. The percent of healthy and variant mtDNA in each oocyte can be unpredictable due to the existence of multiple copies of the mtDNA in each cell. This phenomenon is termed heteroplasmy.

Heteroplasmy has been positively correlated to severity of the disease and/or negatively correlated to age of onset of the disease, but is thought to be one of many factors that contribute to severity and age of onset (Zhang et al, 2009). Typically, the heteroplasmic load of variant mtDNA must reach a certain level before the mitochondrial disease presents, termed the threshold effect (Rossignol et al., 2003).

Another aspect that makes predicting the severity of a child’s disease is that of the bottleneck effect. Copies of the mtDNA are segregated randomly into a woman’s oocytes, meaning that her offspring can have differing levels of variant mtDNA to her, and to each other. This, in part, is why there is a spectrum of disease symptoms seen within families.

Techniques to avoid disease have been developed for genetic diseases arising from the nuclear DNA including mitochondrial diseases. In vitro fertilization (IVF)

3 is an assisted reproductive technology in which the egg is fertilized by the sperm outside of the body, and implanted after fertilization has been successful.

Preimplantation genetic testing for monogenic disease (PGT-M) can test embryos for diseases caused by pathogenic variants in single nuclear genes due prior to implantation. If disease-causing variants are found in the embryo, it is not implanted and another embryo without the variants is chosen to be implanted. This technique is currently offered for mtDNA-based diseases in the clinical setting. When used in this manner, it attempts to screen embryos, choosing those with expected low heteroplasmy (Newcastle upon Tyne Hospitals, 2020). However, it is not an adequate prevention for mtDNA-based mitochondrial disease in embryos because it is less reliable in detecting mutations in the many copies of the mtDNA across the many mitochondria within the cells of the embryo. Due to this increased unreliability, researchers began to explore other methods to help create a child who is not affected by mtDNA mitochondrial disease.

Mitochondrial replacement therapy, at its most basic, involves replacing the mitochondrial DNA with the mitochondria of a donor cell. This results in the nuclear

DNA of the mother being preserved, while the mitochondrial DNA comes from a donor. Therefore, the child will not inherit the mtDNA variant from the mother and as a result will not be affected with the mother’s mitochondrial disease. Multiple methods of mitochondrial replacement therapy (MRT) have been explored, the difference primarily lying in whether the technique is carried out on a pre-fertilization

4 oocyte or a post-fertilization zygote. The preferred method is to use a pre-fertilization oocyte, termed spindle-chromosomal complex transfer (Tachibana el al., 2009).

Spindle-chromosomal complex transfer was first used on rhesus macaque monkeys in 2009 (Tachibana et al., 2009), followed by the technique being used on human oocytes in 2013. Follow-up at the time of the 2013 paper on the rhesus monkeys born in 2009 revealed that they had normal mitochondrial function

(Tachibana et al., 2013). A paper in 2017 revealed that a healthy baby boy was born in 2016 to a woman who had experienced four pregnancy losses and two deceased children (as a result of the mtDNA variant m.8993T>G associated with mitochondrial disease NARP/ Leigh Disease), after use of the now-preferred spindle- chromosomal complex transfer method (Zhang et al., 2017). The doctor was from the

New Hope Fertility Center in New York City, though the therapy itself was performed in Mexico due to legal restrictions in the United States.

This therapy was legalized in the United Kingdom in 2015 (The Human

Fertilisation and Embryology [Mitochondrial Donation] Regulations, 2015). In the

United States, the regulation of this therapy falls under the jurisdiction of the FDA’s

Centre for Biologics and Research. In December of 2015, H.R. 2029 was passed by

Congress, stating that funds may not be made available to the FDA to consider applications to pursue clinical trials for research “in which a human embryo is intentionally created or modified to include a heritable genetic modification”, effectively shutting down avenues of research in which a human life could be created

5 as a result of this therapy (H.R.2029 - Consolidated Appropriations Act, 2016), including MRT. As of the time of this writing, the policy is still upheld by the FDA.

A study in 2016 done by Engelstad et al. gauged interest in MRT in two populations affected by this therapy, surveying 96 mtDNA mutation carriers and 112 potential oocyte donors. They found that there was support from both parties. It was found that 78% of women of childbearing age at risk of having a child with a mitochondrial disease felt that the risk was great enough to consider not having biological children, despite 95% of the respondents considering childbearing saying that having biological children was somewhat or very important to them. Ninety-five percent of all respondents who were at risk of having a child with a mitochondrial disease stated that the development of this technique was “important and worthwhile”, and 87% of potential oocyte donors stated that they would donate oocytes to be used for this technique. One of the limitations of this study was that the participants were recruited only from research-oriented communities and did not gauge the interest in a broader population.

While research has been performed to gauge interest in this therapy, prior to this research no qualitative research has been done on the decision-making factors surrounding MRT. There has been research done on the decision-making factors surrounding PGT-M, which is widely used in clinics to prevent a variety of genetic conditions. Sixteen studies focused on the perspectives of those considering PGT-M were examined in a meta-analysis by Hershberger & Pierce in 2010 that aimed to

6 form a conceptual framework for decision-making factors involved in PGT-M. The main themes that arose from this analysis were cognitive appraisals, emotional responses, and moral judgments. Within the cognitive appraisals theme were success rates of PGT-M, procedural risks (such as a misdiagnosis of an embryo), human risks and safety, financial costs, and timing. Emotional responses included two subthemes - pain and suffering (PGT-M was expected to reduce future pain and suffering for the child and the parents, as well as avoid negative emotions that would come from the heritable nature of these genetic conditions), and joy and happiness (pertaining to the importance of having a genetic link to the child). Moral judgments included status of the embryo (the potential of the embryos and what to do with the supernumerary embryos not implanted), the “technological imperative” of whether or not to use new technology to alter the health status of an embryo, disability and disease prevention, the social significance of the use of PGT-M, and application of PGT-M (Hershberger

& Pierce, 2010). The authors of this paper acknowledge that these factors interact with one another and with other aspects of an individual or couple’s life, and that there may be other factors that may not have been identified in these sixteen studies.

This study offers a rich insight into many of the factors that could be considered for

PGT-M. There may be parallels in considerations for MRT, though MRT displays added complexities due to the direct manipulation of genetic material, differences in inheritance and variability of mitochondrial disease, and legal status of MRT in the

US.

There is a plethora of information available regarding various techniques for performing MRT. Research conducted on the consumer perspective includes one study examining interest and importance of MRT from the perspective of both oocyte donors and women affected with mtDNA-based mitochondrial disease (Engelstad et al., 2016), and research about decision-making factors considered in PGT-M

(Hershberger & Pierce, 2010). However, an in-depth qualitative analysis of motivations and reservations about MRT has not been conducted. Exploration of the factors that influence the decision making process, both positive and negative, regarding MRT would be of great interest to the affected population and medical professionals working with this population to help them make more informed decisions. This data could also be important in the consideration of legalization of this therapy in the United States, giving patients a voice in the conversation about the future of this therapy in the US. The purpose of this study is to discover what motivates patient interest in MRT as an option for their family, and what causes them to be hesitant about pursuing this therapy.

CHAPTER II

MATERIALS AND METHODS

Recruitment

Moderators of the Reddit group r/mito, United Mitochondrial Disease

Foundation Facebook group, and MitoAction Facebook group were contacted for permission to post a participant letter to its members. The moderators were provided a copy of the Qualtrics survey and the interview guide that their members would be asked to complete. The participant letter was posted to these respective groups with an invitation to email the primary investigator if they were interested in participating in an interview about their opinions on mitochondrial replacement therapy (MRT). It is difficult to gauge how many members saw and read the letter as this information is not tracked. These groups collectively have 15,000 members, but overlap is likely and unknown. Interested members were screened for eligibility via email communications and, if eligible to participant, given a link to the Qualtrics survey which included a basic explanation of MRT, gathered basic demographic information, and gauged knowledge about mitochondrial conditions and MRT. This Qualtrics survey collected participants’ contact information and availability to denote they agreed to an interview.

Participants were contacted within four weeks of completing the survey to schedule an interview time. Eligibility criteria included participants ≥18 years old

9 who were either diagnosed with a mitochondrial condition or had a close relative diagnosed with a mitochondrial condition (such as a child), and the mitochondrial disease was due a mtDNA variant, confirmed by family history or genetic testing.

Participants received $20 after completing the interview to acknowledge their contribution to this research.

Development of Materials

A survey was developed to include basic demographic information, questions regarding one’s experience with mitochondrial disease (such as whether the participant was affected themselves, and which other family members were affected, if any), questions asking the participants to self-rate their knowledge on a Likert scale from ‘far below average’ to ‘far above average’ on topics related to mitochondrial disease and MRT, and questions to assist in scheduling an interview.

The interview guide was constructed using decision-making factors relevant to PGT-M found in the 2010 Hershberger & Pierce paper, with additional consideration of factors that are unique to mtDNA-based mitochondrial disease and

MRT, gleaned in part by the 2016 Engelstad et al. paper.

The survey and interview guide were tested with two members of the Reddit group r/mito. The primary researcher gathered the test participants’ feedback on clarity and content of both the survey and interview guide, and revised the materials accordingly before utilizing them with the research participants.

Data Collection - Quantitative

Demographic information and information about knowledge of mitochondrial conditions and MRT were collected via a Qualtrics survey. Participants were also provided with a short explanation and diagram of the process of MRT so that those who had never heard of MRT could also be included in this research. A written consent document was included before the survey questions began. Nineteen responses were recorded over a period of two months. Two respondents did not include their contact information in the survey, four respondents were excluded due to demographic saturation and saturation in the condition the individual was affected by (in an effort to achieve representative sampling), and two respondents were lost to follow up. The eleven participants interviewed were assigned a number so the primary investigator could link the respondent’s survey and their subsequent interview.

Data Analysis - Quantitative

Survey responses were collected via Qualtrics and analyzed using Jamovi statistical software. A two-tailed paired t-test was used to explore any differences in participant knowledge. The researcher opted not to include participants who did not complete the whole study, as this portion of the data was supplementary to the qualitative portion and did not answer the main research questions alone.

Data Collection - Qualitative

Eleven semi-structured phone interviews were conducted over three weeks using the revised interview guide, each interview lasting an average of 31 minutes.

Questions aimed to explore the participants’ previous experience and knowledge of mitochondrial conditions and MRT, perceived benefits of MRT, and reasons not to support MRT. Hypothesized scenarios were included to further probe motivations and reservations. Interviews were audio recorded with permission from participants. A verbal consent request was read to participants and agreement was given prior to starting the interview. This study was approved by California State University

Stanislaus’ Institutional Review Board (IRB) as protocol #1920-017 on September

10th, 2019.

Data Analysis - Qualitative

Audio recordings were transcribed using NVivo’s automatic transcription service and each transcript was reviewed by the primary researcher for accuracy.

Each transcript was de-identified before coding analysis was performed, and each was assigned a participant number corresponding with their survey participant number.

A code book was developed by the primary author and a second coder based on the initial research questions. Each coder used the developed code book to review each interview independently, using NVivo 12 Plus coding software. The first interview was used to synchronize the coding definitions and applications. Any

12 differences in the phrases included in the analysis were discussed until a consensus was reached. Discrepancies generally involved differing interpretations of quotes, but were resolved when context of the quotes were discussed. Coding was an iterative process, in which themes that emerged in later interviews were added to the code book and re-analyzed in previous interviews.

After coding was complete, the primary investigator noted the number of interviews each code arose in, how many times a code was used in each interview, and the significance of each code. The most common, frequent, and significant codes were reviewed and grouped into larger themes based on the overall content and sentiment of the codes.

CHAPTER III

RESULTS

Demographics

The participants of this study were primarily female (82%), and ages of participants were evenly distributed from 25 to 74. Representation from the

Southwestern United States was missing in this study, and there was a lack of ethnic diversity, with all but one participant identifying as white. Most participants (91%) had at least some undergraduate education. Seven of the eleven participants had already had children, and only one participant was considering childbearing in the future. Nine (82%) of participants were affected themselves, five (45%) had affected children, and seven (64%) had other affected family members such as cousins or parents. The majority of participants (64%) were affected by LHON. The demographic information can be found in Table 1.

Table 1

Demographic Information

Number of interview participants

Age 18-24 0 25-34 2 35-44 3 45-54 2 55-64 2 65-74 2

Gender Male 2 Female 9 Ethnicity White 10 White/Asian 1 Region of US Western 4 Midwestern 2 Northeastern 1 Southeastern 4 Southwestern 0 Highest level of education High school 1 Some undergraduate 5 Undergraduate 4 Graduate 1 Children No, not planning 3 biological children Planning biological 0 children in ≥5 years Planning biological 1 children in ≤5 years Have had children 7 Affected in family Affected themselves 9 Children affected 5 Other family 7 members affected (i.e. parents, cousins, etc.)

Knowledge About Mitochondrial Conditions and MRT

Participants (n=11) were asked on the survey to rate their knowledge on more general topics related to mitochondrial disease (questions 1-4), and to rate their knowledge on the process of MRT (question 5):

1. How would you rate your understanding of what the mitochondria do in the

body?

2. How would you rate your understanding of how mitochondrial DNA

conditions are inherited?

3. How would you rate your understanding of the variability of mitochondrial

conditions (i.e. range of severity)?

4. How would you rate your understanding of the difference between

mitochondrial DNA and nuclear DNA?

5. How would you rate your understanding of the process of mitochondrial

replacement therapy?’.

Participants rated their understanding on a Likert scale from ‘far below

average’ to ‘far above average’. These ratings were converted to numerical values

to aid in quantitative analysis, with one corresponding to ‘far below average’ and

five corresponding to ‘far above average’. See Figure 1 for the Likert scale used.

Figure 1. Likert scale. This figure demonstrates the scale used to gauge self-rated knowledge of questions pertaining to general mitochondrial disease topics and self-rated knowledge of the process of MRT.

The mean self-rated knowledge score reported by the participants for all five questions was 3.82, which corresponds to ‘average’ to ‘slightly above average’

(MD=3.82, SD=0.756). Included below in Table 2 are the descriptive statistics of the overall knowledge scores.

Table 2

Descriptive Statistical Information on Participants’ Overall Self-rated Knowledge Score on the Survey.

Overall knowledge score at survey

N 11

Mean 3.82

Standard deviation 0.756

When knowledge questions were separated out by relatedness to MRT, differences arose in the data (see Table 3). On average, participants rated their knowledge higher for general mitochondrial disease topics (questions 1-4) (MD =

3.95, SD = 0.697), while the average self-rated knowledge score for MRT (question

5) was lower (MD=3.27, SD=1.19).

Table 3

Descriptive Statistical Information on Participants’ Average Self-rated Knowledge

Score on the General Mitochondrial Topics and Average Self-rated Knowledge Score on MRT Alone.

Mito knowledge - No MRT MRT knowledge score at survey

N 11 11 Mean 3.95 3.27 Standard deviation 0.697 1.19

Figure 2 shows that while three participants (27%) had the same level of knowledge for general mitochondrial knowledge and MRT-specific knowledge, the remaining eight of participants (73%) reported lower levels of knowledge about MRT than knowledge about general topics relating to mitochondrial conditions.

4.75 4.75 4.5 4.25 4.25 4 4 4 4 4 4 4 4 4 4

3.25 3.25 3 3 2.5

Overall knowledge

1 1 MRT knowledge

Figure 2. Bar graph. This bar graph demonstrates self-reported knowledge at time of survey about general mitochondrial topics vs. MRT.

A two-tailed dependent samples t-test (see Table 4) showed that the difference was statistically significant with a large effect size, t(10) = 2.86, p=0.017, d= 0.862.

Table 4

Dependent Samples Statistical T-test Determining if Difference Between General Mitochondrial Knowledge and MRT-specific Knowledge is Significant.

Cohen's statistic df p d

Mito knowledge - MRT knowledge Student's 2.86 10.0 0.017 0.862 No MRT score at survey t

The participants were also asked if they had heard of MRT prior to the survey

– eight of the eleven participants had, while three had not.

The findings below report key themes that arose from the eleven interviews conducted and have been grouped under the main portions of the interview guide: personal experiences, motivations, and reservations. As MRT has not been legalized in the US as of this time, the opinions expressed are regarding hypothetical implementation of this therapy.

Personal Experiences

Personal experiences contribute to the way participants viewed this therapy.

These experiences included negative interactions with providers and poor quality of information received about mitochondrial disease. Support can help alter how patients perceive their experiences. Sources of support were shared by participants in this study, as well as its importance in the lives of patients with mitochondrial disease.

Trust in the Scientific and Medical Community

Eighty-two percent of participants recounted poor experiences with the medical system in the past, either directly through interactions with healthcare providers or through the frustration of a diagnostic odyssey. The stories from the participants of self-advocacy and navigating through the medical system were each unique, but contributed to a common thread of undermining their trust in the medical system:

And the doctors didn't believe me that I couldn't see, they told me I was crazy.

Told me I should go to a mental institute because I made myself believe I

couldn't see. So that experience right there was probably the worst part. [...]

The hardest part was not knowing anything, or not being able to ... The

doctors couldn't see it. Everything I tried to do they couldn't see or figure it

out. That's the most frustrating part, was waiting for that. – Participant 6

Twenty-seven percent of the total number of participants, a third of the group who shared poor personal experiences with the medical system, also expressed concerns about the credibility of information received, though their stated preference for where they wanted to receive information from differed. When asked where they wanted to receive information from and given examples of “online, physician, patient groups, foundations, other families, etc.”, two participants stated:

Any of the above, especially patient groups. Most of my doctors aren't

familiar at all of any kind of mitochondrial disease or specific ones.

– Participant 3

I prefer to hear it from whichever medical entity was doing it, because I

found out repeatedly that doctors that are not thoroughly knowledgeable about

a subject can give you misinformation. Yes. And not, and not intentionally.

But [...] they just don't know what they don't know. And you end up making

decisions based on bad information. – Participant 8

27% of participants expressed that they would prefer to hear information from those performing the therapy, 18% stated that they placed more trust in the

21 experiences of other patients, and 27% mentioned both sources of information. Only

9% of participants stated that they would want to receive this information from doctors. The concern felt by the 27% of participants about the credibility of general information about mitochondrial diseases offered by certain providers also extended to MRT specifically. One participant who had also participated in a clinical research study surrounding MRT felt misinformed about the study’s intended outcome:

You know, in the context of the study it was, I would say, maybe a little more

disorganized than I had hoped or expected. And I also felt that the original

meeting, I guess I was, I thought there was a greater chance that the end result

of this study down the line would, would perhaps result in - the second part of

the study being that they would be able to implant an embryo and move

forward and kind of actually create a life out of this . But then I was not very

well informed of the fact that they are not allowed to do that even on a

research basis because of laws. – Participant 10

Participant 10 expressed trust in the scientific community despite this lack of clarity. After sharing possible ‘worst case scenarios’ that could come out of MRT involving efficacy and safety concerns, she stated:

You know [...] I have to say very strongly they’re actually really not worries

of mine. I can't imagine that being two scenarios that could happen, but I don't

know why. It just feels to me that it's not likely. Maybe I'm naive. Maybe I

have a lot of trust in the science. Maybe I feel like nobody would proceed

with, with that, creating a life, if they weren't really certain of the procedure. I

don't know. I don't, I don't think I really would be very worried about it at all.

– Participant 10

Support of Patients with Mitochondrial Disease

Fifty-five percent of the participants shared some of their sources of support, particularly when issues surrounding mitochondrial conditions came up. One participant shared the support and insight that she receives from the LHON community, and the stark contrast it is from her mother’s experience with LHON:

As I say, my mother wandered literally in the darkness for years before they

even put a name to what was wrong with her. And other than her uncle, who

was still alive, knew no one else with this condition. And I compare that to

what (son) has, with an annual gathering of this group together. What I have

as a carrier, and a potential affected person. What I've been able to share with

my siblings and my younger son and my nephews. And it's, it's incredible. It's

a world of difference. It has, it has let all of us plan for that eventuality that we

never even considered before. – Participant 2

Another participant shared that those with chronic illnesses other than mitochondrial disease have proven to be a good source of support as well:

I've got some really good close friends who also understand. They have some,

although not nearly as serious, they have suffered from some illnesses,

chronic illnesses and pain too. It’s a good sounding board. They get it.

– Participant 10

Another concern raised in 27% of the interviews was the effect of the participant’s own health on being able to parent a child, even if MRT was an option for them:

I have been just a little bit sick and gotten more sick as time went on. It's been

really very physically demanding to take care of sick kids. And as I mentioned

earlier, I wish I could have had the energy to do what I felt was best for my

kids in every area… I feel like you need to be fairly healthy to be able to take

good care of a child, and if you're not, you need to be very rich and lucky to

have good people to take care of your kids. – Participant 8

Motivations

Overall, all eleven (100%) of the participants were grateful that progress was being made in the prevention of mitochondrial disease. MRT represented hope for

91% of the participants, as it offers a way for those affected with mitochondrial disease to have children that will be free of symptoms. This therapy preserves a biological link to a child, which was of importance to 27% of the participants. This therapy also represents a way to avoid negative outcomes for children and their parents by preventing the appearance of symptoms in children (73%), stopping the continuation of mitochondrial disease through generations (73%), and avoiding

24 negative feelings that might arise from the heritable nature of mitochondrial disease

(64%).

Hope and Progress

The reason scientists began to explore MRT was to help those affected with mtDNA-based mitochondrial disease have healthy biological children. For all eleven

(100%) participants that were interviewed, the development of a therapy that reintroduces the option for biological children without mitochondrial disease is an exciting breakthrough:

Thank God. I'm so glad it's a possibility. To me, it's like, you know, finding a

cure for polio, if you can prevent babies to be born that will suffer. I mean,

obviously there are things you can't prevent, and you can't know everything

and solve everything. But if you know there is a problem and you can fix it,

then then that's great. Kids, people that wouldn't want to have a child

otherwise can have one. Children that would suffer terribly can have their

suffering alleviated. – Participant 8

Forty-five percent of the participants stated that MRT would just be one option for having children, with adoption the most often mentioned alternative by

36% of the participants. While the biological link may not have been as important for these participants, another 27% of participants stated that having biological children was very important to them. One participant who had not had biological children had

25 chosen not to be a mother for other reasons not related to mitochondrial disease, though she did state:

I told my husband it was a really cool thing , a really good option, because,

you know, as a woman, it is a hard pill to swallow, even if you don't want

children, to have that option taken away. – Participant 4

Avoidance of Negative Outcomes

The potential of this therapy to improve the lives of people who would have been affected with mitochondrial disease was one of the biggest motivations that arose as part of the interviews, with 73% of participants citing it as a reason that they support it. One participant, who has vision loss due to LHON, discussed the perspective he has heard expressed from sighted people, and how his experience informs his opinion of this therapy:

When I talk to other people about things, they think, ‘Oh, no, you shouldn't.

That's playing God, you shouldn't touch things, can't mess with somebody's

DNA.’ They do not understand that life would be dramatically better without

a disease. – Participant 5

Not only did 73% of participants feel that MRT would offer the opportunity for better lives for future generations, these same participants felt a responsibility to attempt to create better lives for future generations. When asked about the main motivation for supporting MRT, Participant 6 stated:

So my family can have healthy children. Not have this, it's horrible. I don't

want my grandkids to go blind like I did. I don't want anyone, not from my

family and everybody out there, obviously, to go through this at all. So I think

my biggest reason for doing any research or being in any of these studies I've

been in is for future generations. – Participant 6

Sixty-four percent of the participants shared negative feelings due to passing a mitochondrial disease to their children or at the idea of passing a mitochondrial disease to their children, as illustrated in this interaction with Participant 3:

Participant 3: Well, when I found out I had it, and that I gave this to my three

children, I felt very guilty. I didn't know anything was... you feel really guilty

as a mother that I passed this along unknowingly. Some families know about

it and still choose to do it. I mean, that's their prerogative. I think most people

wouldn't want their child to struggle with major health issues and/or

blindness. If I can avoid it.”

Interviewer: If you were to have used the therapy like this, do you think you

would feel differently?

Participant 3: Yeah I wish it would be available to me or my family. Yeah.

That would be a wonderful opportunity.

While 64% of participants shared feelings of guilt, 18% of participants stated that they did not feel guilt about the hereditary nature of mitochondrial conditions:

And the reality is, I don't get credit for all of his great genetic characteristics.

And I'm not to be faulted for this mutation. It's just the total package that went

to my son. I have nothing to do with it. That's how I look at it. – Participant 1

Reservations

Participants expressed concerns with both the process of MRT, as well as its wider implications. All participants (100%) cited at least one concern associated with

MRT, the most common concerns being cost, safety, and efficacy. Additional reasons that these participants would be hesitant to try MRT included availability and the novelty of the therapy. In addition, 18% of participants acknowledged the risk-benefit trade off of a therapy like MRT and questioned its use for less severe mitochondrial conditions, as well as uses not related to mitochondrial disease. 27% of participants also anticipated that new technologies would be introduced in the future that may render MRT redundant. In addition, 45% of participants were wary of the social implications of this therapy, including scientists ‘messing with nature’, paving the way to the advent of ‘designer babies’ (the colloquial term for non-therapeutic genetic manipulation).

Concerns with the Process of MRT Itself

Although all eleven (100%) were supportive of MRT, the participants interviewed were also aware of the risks and obstacles that this therapy may carry with it. When discussing cost, participants were given a cost associated with

28 preimplantation genetic testing – between $14,000 and $25,000 for IVF, medications, and PGT-M (Advanced Fertility Center of Chicago, 2020). The differences were explained to the participant and cautioned that while it’s difficult to estimate cost due to the lack of availability in the US, likely the cost of MRT would be more due to the added complexity of manipulating the genetic material rather than merely testing it.

91% of the participants stated that the cost would be a barrier to accessing this therapy. Forty-five percent of participants then compared the cost of MRT with that of other costs associated with raising a child, and felt that it would be a reasonable cost to have a healthy child. One participant discussed the gene therapy trials that have occurred for Leber’s Congenital Amaurosis patients, quoting a price of

$850,000 (Darrow, 2019) and felt that in contrast, a price closer to $14,000 to

$25,000 would be much more accessible. Three of the participants mentioned the compounding factor of disability on the finances of people with mitochondrial conditions:

It's probably pretty reasonable for the medical community. But when you have

LHON you get put on disability and I get 900 dollars a month, that's my

income so I couldn't, I wouldn't be able to afford it. – Participant 6

Eighty-two percent of participants mentioned concerns about the safety of the procedure at least once in their interview. Safety was the most frequently cited concern in these interviews, mentioned 30 times, with the second and third most commonly cited concerns being cost and efficacy at 21 and 20 times mentioned,

29 respectively. Some of these concerns arose from the belief that the process is more complicated than scientists currently believe, that screening for disease-causing factors in the donor egg will not be rigorous enough, or that a new medical issue such as cancer would be introduced to the child as a result of this therapy.

The concern of the health of the patient themselves was raised in 36% of the interviews. Although only 36% of the participants mentioned this topic, it was a major concern for these individuals and was discussed at length. Twenty-seven percent of the participants mentioned that the process of MRT (such as egg retrieval and a pregnancy itself) would cause hesitation in proceeding with a therapy like this:

I think that would be my only concern moving forward is when you have a

mitochondrial disease, right, and you're already, there's already so much

imbalance and dysfunction in your body and your organ systems. And then,

you know, to go through an egg retrieval for a normal person is a pretty, not

only is it pretty invasive, but it's also really difficult on your body as far as the

hormone injections and all things like that. But when you do that with

somebody who’s got mitochondrial disease, it's compounded tenfold.”

– Participant 10

Even if you were to get an egg and be able to carry it yourself with the

corrected mitochondrial disease, just the toll that having a pregnancy does on

a body that already has mitochondrial disease. To me, it was devastating. I

mean, I was debilitated, stuck in bed for two years after I had my son. I

couldn’t pick him up, stuff like that. Like it was really bad. After my daughter,

I started the dysautonomia stuff where if I stood up too long I’d pass out, or

too fast or whatever, you know, for like three years. I was in a wheelchair,

motorized so I could get around. To me, while this might be a good solution,

unless you're planning on using a surrogate, it can also still be quite damaging

to yourself. – Participant 11

Ninety-one percent of participants also had concerns about the efficacy of the procedure – specifically, that a person with mitochondrial disease would overcome the barriers to access this therapy, navigate the safety concerns, and have a child that still has a mitochondrial condition. One participant emphasized the need for clear expectations in this process for participants:

So, going through the physical challenges and going through the cost

expenses, and it's ineffective? I mean, frustrated, angry […] Until about a year

or two ago, I think I was generally getting the sense that it's an easy approach

and it's a 100 percent solution - zip zip you're done. And now there's starting

to be this creeping, I'm not so sure. So, yeah, the hard part is, part of it is when

rubber meets the road, what's the expectation? And I guess if the outcome

matches the expectation, if we were all informed going into it, and it's really

not as perfect a solution as we, as I currently envision it, and it matched that ...

I guess I wouldn't be as angry or frustrated. – Participant 1

One logistical concern 45% of the participants had was that of availability.

One participant, when asked about whether she would consider accessing this therapy in an alternative way such as moving to another country, said:

I get pretty upset with how far behind we seem to fall in the United States on

certain things. Usually, usually due to political reasons and political reasons

are, in my opinion, political influences that have no right to have any bearing

on the topic... I know it seems crazy to pick up and move to a whole new

country. But just for that opportunity. That's really what I would be seeking.

Just the opportunity to be able to do that.” – Participant 10

This willingness to try MRT in an alternative way was expressed by 64% of participants when asked.

Fifty-four percent of participants expressed hesitation due to the novelty of this therapy, sharing feelings of not wanting to be “the first one”, and 45% of participants expressed that they would need more information before being comfortable with MRT.

Necessity

One consideration that 27% of all participants brought up was the necessity of

MRT for those with less severe disease, and whether the opportunity to have a biological child without the condition outweighed the risks of MRT. Of the seven

32 participants whose familial mitochondrial disease was LHON, 43% of that group shared their considerations when balancing the risks and benefits of a procedure:

Just might also depend on what the affected rate is, what the mitochondrial

disease is. It's kind of very debatable in terms of who's going to get affected

with LHON.” – Participant 7

Conversely, the remaining 57% of the group whose families were affected with LHON identified that their mitochondrial condition has had a devastating effect on their lives, and it can have effects on body systems other than the eyes as well

(termed LHON+). Interestingly, 67% of those who felt that the risks of MRT may outweigh the benefit of having sight were not affected themselves.

An issue explored with participants was the use of MRT for reasons not related to mitochondrial disease such as infertility, which has been legalized in the

Ukraine and has been performed at the Nadiya Clinic (Pompei & Pompei, 2018). It should be noted that the researchers conducting the study on the use of MRT for infertility have since published that there were no benefits of using MRT for this purpose (Mazur et al., 2019). While 55% of the participants stated that they did not have concerns about the use of MRT for this purpose, there were a multitude of concerns stated by 27% of participants. Eighteen percent of participants were concerned about the therapy being used for this purpose being ‘too far’, believing that this therapy should be reserved for applications related to mitochondrial disease, raising the concern of the risk vs. benefit trade off of this therapy. One participant

33 stated that conversations about MRT being used for infertility derail the conversation about MRT being used for mitochondrial disease in the current climate:

I certainly am not for taking away anybody's abilities to carry out their lives

and in the manner in which they want to. But I also think that those are the

types of conversations and considerations that in this stage of the game are

kind of a hindrance to the purpose of the procedure in the context of my

disease. I think those are the conversations that raise eyebrows and make

people say that this is a technology that can get out of hand or causes the need

for, I guess, people to be leery of it and over-suspicious of the uses of it and it

being used, misused. – Participant 10

Twenty-seven percent of the participants expressed the belief that a therapy will be introduced that renders MRT unnecessary. Eighteen percent of the participants discussed their anticipation of upcoming research and therapies that would treat or cure mitochondrial disease, and one person specifically cited CRISPR as a new avenue for development of genetic therapies.

The ‘Slippery Slope’

Finally, 45% of participants expressed hesitation around starting down a

‘slippery slope’ of manipulating genes. Thirty six percent of participants specifically alluded to the idea of ‘designer babies’ and making cosmetic changes to children through genetic manipulation. Eighteen percent of participants stated that MRT was

‘messing with nature’ – though the participants differed on whether this felt like a reasonable risk to take:

I think to be honest, if I didn't have a disease that is not able to be cured by

any other means, I probably would not look to do a therapy like that. Because

I think it's a big thing. I think it's messing with nature. But I also think that

that it can be really good for people who really feel that they have no other

option. – Participant 9

When asked to elaborate on their stated religious reservations, Participant 11 shared their family’s religious beliefs and the conflict they present with MRT:

Well, we're Catholic, so we don't believe in messing with the egg or sperm in

any way. They should be done naturally, that sort of thing. – Participant 11

CHAPTER IV

DISCUSSION

Influences of Personal Experiences

As mentioned in the 2010 Hershberger & Pierce meta-analysis, the interplay between various factors in patient lives is an important consideration when examining patients’ decision-making processes. Patient decisions are affected by a variety of factors – both related to the decision in front of them, as well as other influences in their lives. One such factor identified in this study was that of previous experiences with the medical system. Many participants recounted stories of diagnostic odysseys, not being believed by providers, and other negative interactions with the medical system. This can contribute to a feeling of mistrust toward healthcare providers that permeates into their decision-making process surrounding MRT.

Motivations for Own Family

Motivations that were identified in this study included a renewed hope in the ability to have a biological child unaffected by mtDNA mitochondrial disease, and avoidance of negative outcomes – similar to findings in the 2010 Hershberger &

Pierce paper. Previously, choices for women affected with mtDNA-based disease were limited to not having biological children, or risking having a child affected with mitochondrial disease. While 45% of participants did not feel that having biological

36 children was important to them, 27% of participants in this study did. This figure differs greatly from the 2016 Engelstad et al. paper, which found that 95% of women at risk of having an affected child who were considering childbearing felt that having biological children was somewhat or very important to them. This likely can be attributed to the difference in demographics in this study. As most participants were not of childbearing age, and many had already had children, they may have placed a different importance on having a biological link to a child now than they would have before having biological children. Supporting this theory is that only one participant in this study was considering childbearing in the future, and she expressed that having biological children was very important to her.

The other option previously available to these women was to risk having a child affected with mitochondrial disease, which comes with its own challenges.

Sixty-four percent of participants expressed negative feelings, such as guilt, associated with passing a mitochondrial disease onto their children. While two (18%) of the participants expressed a lack of guilt about passing the condition on, the opportunity to relieve some families of the weight of the maternal inheritance of mtDNA mitochondrial conditions cannot be ignored. This feeling of having no ideal reproductive option for those at risk of having a child affected with a mtDNA-based mitochondrial disease sets the stage for excitement at the introduction of MRT.

Broader Benefits

MRT was perceived as an exciting breakthrough by all participants in this study. Many felt that it was a method to improve the lives of children, in comparison to what life would be like if they had been born with mitochondrial disease. Whether the symptoms included blindness or wider systemic issues, participants saw the value in the avoidance of mitochondrial disease. MRT was perceived to be a source of hope for future generations, with 73% of participants expressing that stopping the continuation of mitochondrial disease is one of their reasons to support MRT. In

2016, the National Academies of Sciences issued a statement saying that while MRT does constitute heritable germline modifications in females, it would not be considered a heritable germline modification in males as the effect of MRT would not be passed onto the next generation. They stated that MRT would be permissible to use in male embryos to “prevent potential adverse and uncertain consequences of

MRT from being passed on to future generations.” The committee then offered guidelines advising how to expand this research to female embryos if the initial trials with male embryos were successful (National Academies of Sciences, 2016). Despite this, the 2016 congressional bill H.R. 2029 has been upheld, preventing the FDA from evaluating clinical trials that involve heritable genetic manipulations.

Evidently, a lasting effect throughout the generations is one of the motivations for those affected with mitochondrial disease, while also serving as a reservation for the governing bodies of the United States. As this is a new therapy, there is no

38 published data about how many generations the effects of MRT might last, though a computational model does exist. Pompeii and Pompeii (2018) showed that “the number of generations until extinction of a female-transplanted mtDNA line was 4.7 on average, and 90% of cases were under 12 generations”, which differs from nuclear

DNA changes that can exist indefinitely. Exploring the effects of introduced mtDNA changes could be an avenue into heritable germline modifications on a broader scale, to be expanded to nuclear DNA modifications if successful.

Reservations with Process of MRT

Many of the reservations that were identified in the 2010 Hershberger &

Pierce regarding PGT-M were echoed in this study about MRT. The success rate (or efficacy, as termed in this paper) was a large concern for participants. This consideration could also have been affected by how large participants perceived the barriers to be – if the participants perceived the other factors such as accessibility, cost, and safety to be large barriers, they may be more affected by the idea that the therapy would not be as effective as they had hoped. Recent studies have, in fact, suggested that MRT may not be as effective as once predicted. In a study by Kang et al. in 2016, it was shown that some of the embryonic stem cell lines that had undergone MRT gradually lost the donor mtDNA and reverted to the maternal mtDNA copies. It was found that mtDNA carrying a point mutation for MELAS holds a replicative advantage over wild-type mtDNA (Yoneda et al., 1992). In the context of MRT, a minimal amount of maternal mtDNA transferred may replicate

39 faster than the donor mtDNA, reverting the cells back to the original maternal mtDNA. While some factors have been identified that drive this reversion and research is being done on ways to prevent it, this study supports the idea that MRT is not as straightforward as once thought. Efficacy also factors into the consideration of

PGT-M for nuclear DNA or mtDNA mitochondrial disease patients – while it does represent a way to limit the risk of transmission of the mitochondrial disease to the next generations, it has limited efficacy and may pose safety risks if the patient has to undergo multiple rounds of IVF.

A new finding discovered through this research is an increased level of concern for the safety of the patient due to the patient’s own mitochondrial disease.

Mitochondrial disease patients have been shown to be more susceptible to complications in relation to pregnancy (Karaa et al., 2019), and this may also be seen when undergoing the process of IVF. In addition, it is also possible that introducing heteroplasmy from the donor and recipient mitochondria as a part of MRT, even if unintentional, may introduce its own problems. Sharpley et al. showed in 2012 that mtDNA heteroplasmy, derived from two different mouse lineages, caused altered behavioural and cognitive performance in the resulting mouse in comparison to mice homoplasmic for the cell lines used. It would be difficult to repeat this experiment in humans, though elevated levels of mtDNA heteroplasmy found in older adults were found to be associated with impaired cognitive function, hearing, vision, and walking speed (Tranah et al., 2015). Taken together, this research suggests that heteroplasmy could independently have negative effects in humans. Given that reversion to the

40 maternal cell line has been observed before, this is an area that requires more research in order to understand the full safety implications of MRT. Due to the novelty of both

PGT-M and MRT, unforeseen consequences of these therapies for the child were factors in decision-making found both in the Hershberger & Pierce study and this research.

While financial considerations were factors for patients considering PGT-M in the Hershberger & Pierce paper as well as participants considering MRT in this research, disability due to mitochondrial disease was a unique consideration in this realm. When ill health precludes mitochondrial disease patients from working, disability further compounds concerns over the cost of a therapy such as MRT. While a hypothetical figure was given to participants in this study, the participants on a limited income would need assistance regardless of the exact cost of the therapy. If this therapy is introduced, discussions about public health and coverage by insurance companies will need to be had. The lifetime costs of caring for a person with mtDNA- based mitochondrial disease may outweigh the cost of prevention via MRT, factoring into the necessity of coverage for this therapy.

Lastly, legality and availability remain critical factors in access and opinions regarding this therapy. Availability of the therapy was a concern for 45% of participants, with 64% of the participants expressing that they would consider accessing this therapy in an alternative way, such as going to another country. This

41 represents a loss of the government’s ability to oversee this process, and potentially introduces a risk to the safety of Americans who might choose this route.

Societal Concerns

There were also societal implications considered by participants in this study.

One such consideration was that of necessity. Forty three percent of the participants affected with LHON identified their own disease as a less severe mitochondrial disease and considered the risks of MRT when weighed against the benefit of avoiding blindness. While this may not be worth the risks to these participants, the other 57% of participants with LHON shared how devastating the disease has been to them – these might be patients for whom the benefits would be worth the risks.

Some research has been conducted on the range of severity of conditions for which patients pursue PGT-M. Spor et al. (2019) examined 481 conditions for which

PGT-M was pursued from 2013 to 2018. When conditions were classified by the

Family Systems Genetic Illness Model, it was found that 29% were adult onset conditions, 33% were conditions that display reduced penetrance, and that treatment could alter onset or progression in 60% of conditions. Though the majority of conditions were considered severe, 22% were of moderate severity and 18% were of low severity.

While PGT-M is available for these types of conditions, both patients and providers grapple with whether this is an acceptable application of this technology, as

42 found by Klitzman in 2018. These conditions are considered to be in the ‘grey area’, either due to age of onset, variable penetrance, or variable expressivity. Some of the dilemma arises from whether the patient and provider consider the condition to be a disease, disability, or as falling within the spectrum of normal human traits.

This personal consideration about whether certain effects of mitochondrial disease, such as blindness caused by LHON, are disabilities will affect a person’s perception of the necessity of MRT. An interesting finding is that 67% of those who raised the question of the risk vs. benefit ratio of MRT for LHON were not affected themselves. The personal consideration and impact of blindness likely played into whether the participants whose families are affected by LHON felt MRT is necessary.

The ever-increasing speed at which progress is being made raised the question for 27% of participants about whether a new therapy will be introduced that renders

MRT unnecessary. Therapies are being explored that would reduce symptoms in people who are already affected by a mitochondrial disease, such as mitochondria- targeted endonucleases. These endonucleases (such as ZFNs and TALENs), as well as technologies such as CRISPR, work to shift the heteroplasmy of the mitochondria in a person to below the threshold at which the disease presents (Jackson et al., 2020).

While studies exploring these technologies have been encouraging thus far, there will likely remain a role for a therapy that aims to prevent disease rather than correct it.

The same logistical decision-making factors (efficacy, safety, novelty, cost, accessibility) identified in this research will likely also be pertinent for consideration

43 of upcoming therapies, and there will likely be consumers who decide that the risks associated with MRT are preferable to those of any future novel therapies.

One of the considerations in the Hershberger & Pierce paper is that of the application of the therapy, falling under the larger grouping of moral judgments. This same concern arose when discussing MRT for infertility. While 55% of participants did not express disapproval about MRT being used for this purpose, many participants cited the risk vs. benefit trade off, and questioned whether this application of MRT would be going ‘too far’. This idea of ‘going too far’ was expressed by 45% of the participants as a concern for MRT in general, termed the

‘slippery slope’ concern.

With each introduction of a new therapy involving assisted reproductive technology, from the first child born in 1978 after a successful IVF procedure, to the first baby born in 2018 after the use of CRISPR (Cyranoski, 2019), the ‘slippery slope’ concern has been cited by the public. The idea that these new technologies are opening the floodgates to unethical use of reproductive technology is not a new concept. This concern was also cited by 45% of participants in this study, with considerations made for the implications of ‘messing with nature’ and religious beliefs. While not a personal concern of most of the participants who mentioned

‘designer babies’, it was mentioned by 36% of participants. It is notable that in this group, many of whom were familiar with MRT before this study, this was still a topic that arose. It is likely that this will also be a concern for the public, who may be less

44 familiar with mitochondrial disease and genetic technologies, as well as the cautious nature of the US laws surrounding MRT at this point. The US government evidently recognizes the responsibility that they hold to regulate new genetic therapies, and as outlined in the 2016 committee statement (National Academies of Science, 2016), will be introducing these therapies in a careful and conscientious way. However,

Keefe (2019) identified that there are financial and political influences on artificial reproductive technologies in the current climate, and MRT is likely not exempt from these effects. While these ethical concerns are valid, the potential of this therapy to improve the lives of those at risk of passing on mitochondrial disease to their children should also hold considerable weight.

Recommendations

Some of the insights that arose from this research were recommendations for providers if this therapy is introduced to the United States in the future. One of the main needs identified by this research was for more information and education regarding MRT. The survey portion of this study identified a gap in knowledge about MRT compared to participants' general knowledge about mitochondrial diseases. The need for more information was expressed by 55% of participants in the interviews, though the preference for the source of information was not agreed upon by the participants. The most trusted sources were found to be researchers and other patients, whereas only 9% of participants stated that they would want information from doctors. Regardless of the preferred source of information, 27% of the

45 participants questioned the credibility of information received, particularly in light of their negative experiences with the medical system. It is important that there are a variety of sources of credible information for patients to access if they are considering undergoing this therapy.

Much of the information regarding the risks of MRT is held within scientific papers. For patients to make informed decisions about this therapy, this information needs to be distilled into simple information that can be understood by those with a range of scientific literacy. Genetic counselors are well-equipped to fill this role, as the profession is focused on translating scientific data into accessible patient-level information. They are specifically trained in delivering information to patients and managing patient expectations. Patient expectations are particularly pertinent with the introduction of a new technology like MRT. As was identified in this research, patients desire clear expectations of efficiency of the therapy, as well as outcome.

Clear communication about these topics, especially in the early stages of the introduction of MRT, will allow for a better informed experience for the patient.

The need to consider factors in a patient’s life outside of MRT has arisen multiple times over the course of this study. One factor identified in this study is the concern of how the patient’s mitochondrial disease will impact their ability to parent a child. To optimize the patient experience, it is important that the patient is supported both psychologically and more broadly. Participants identified that support, both from mitochondrial disease communities and chronic disease communities, was helpful in

46 coping with their own disease. The patient’s health, as well as their surrounding support system, needs to be considered to ensure that the child’s well-being will not be negatively impacted by their parent’s mitochondrial disease.

Limitations

One of the most obvious limitations to this research is the small sample size.

Even within the participants interviewed in this research, it was obvious that people with mitochondrial disease are a heterogenous group with varying concerns, and there are almost certainly aspects of the experience of having mitochondrial disease that were not captured in these interviews. Additionally, due to low response rate, there was a lack of desired diversity in this participant group, particularly in the mitochondrial disease that most participants were affected by. As LHON is considered to be on the less-severe end of the mitochondrial disease spectrum, their views may not be representative of those with more severe mitochondrial diseases.

Using online support groups for recruitment may have introduced selection bias, choosing more connected and informed participants who may have been more likely to support MRT. One of the most difficult limitations about this research is that this therapy is not being performed currently in the US due to legal restrictions, making these opinions about a hypothetical experience. While many of these considerations will likely remain pertinent if MRT is legalized, some of the opinions expressed in these interviews may not be applicable.

Future Research

Future avenues in research that could be employed to expand on this work and address the limitations include other recruitment methods, such as attending conferences and recruiting from medical centres, specifically seeking participants who fill the diversity gaps identified within this research. Revisiting this research once the US government approves MRT to be studied would expand this research from hypothetical opinions into opinions more grounded in the therapy as it would be used in clinic. Utilizing the same questions, adjusted to include additional information, would help identify any unaddressed needs in the community and resources that would be helpful for participants to have a positive experience using

MRT if legalized in the US. This research, as well as these additional proposed areas of research, have the potential to help the medical community meet the needs of their patients more effectively and add the patient voice to a conversation about MRT that has long been dominated by government representatives and scientists.

CHAPTER V

CONCLUSION

This study offers preliminary insight into the motivations and reservations that the mitochondrial disease community hold regarding mitochondrial replacement therapy. While it offers hope for having offspring unaffected by mtDNA mitochondrial disease, this enthusiasm comes with concerns. The motivations and concerns are often intertwined in a cautious optimism, and are influenced by external factors in a person’s life. The themes that arise from this research include concerns about the process of MRT itself, questions of necessity, hope and excitement about scientific progress, the importance of trust of patients in the medical community, and the resources that are important for this community to succeed in navigating MRT.

These considerations may be useful in the conversation surrounding the legalization of this therapy, as well as optimizing the experience of MRT for patients who may choose to pursue it if legalized in the US.

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APPENDICES

APPENDIX A

PARTICIPANT LETTER

Hello,

My name is Suzanna Tai and I am a Master’s student working under the supervision of Dr. Janey Youngblom at California State University Stanislaus. The reason that I am contacting you is that I am conducting a study as a part of my degree in Genetic Counseling titled Mitochondrial Replacement Therapy: Factors in

Decision Making. The purpose of this study is to be able to understand the opinions surrounding mitochondrial replacement therapy from the perspective of families affected by mitochondrial conditions. The goal of this study is to better inform healthcare providers and those involved in deciding the legal status of this therapy from the family perspective, as well as being a source of information for other families who might consider this therapy in the future. Information will be provided to you about this therapy prior to your participation. If you have no prior knowledge of this therapy, participation is still encouraged.

Participation in this study involves a preliminary survey in order to gather demographic information, determine your prior knowledge of a number of basic topics related to mitochondrial conditions, and to provide some information about what mitochondrial replacement therapy is. The second part of this research involves a 30 to 60 minute long interview conducted by phone or video call. I will be asking questions about your knowledge of mitochondrial replacement therapy, factors that

58 might motivate you to pursue this therapy, and factors that might contribute to having reservations about this therapy. Any data collected from this study will be de- identified. In appreciation of your time commitment, you will receive $20 upon completion of the interview. This study has been reviewed and received ethics clearance through the California State University Stanislaus Institutional Review

Board.

If you are interested in participating, please click the following link: www.

After completion, I will contact you within four weeks to arrange a time for an interview if you are still interested. Any questions can be directed to me at the email below or my advisor at [email protected].

Sincerely,

Suzanna Tai [email protected]

Master’s in Genetic Counseling Candidate

California State University, Stanislaus

APPENDIX B

SURVEY

Mitochondrial Replacement Therapy: Factors in Decision Making

Purpose of the Research

The Principal Investigator, Suzanna Tai, is a student at California State University,

Stanislaus conducting research for a master’s degree in Genetic Counseling.

This research includes two parts - an initial survey followed by a phone interview.

The purpose of the survey is to explore understanding and opinions surrounding mitochondrial disease and mitochondrial replacement therapy.

Procedures

Your participation in the survey will require less than ten minutes and is completed online on a computer or mobile device.

Participation in the interview will require approximately 45 minutes and will be conducted by phone or video call.

Participants must be over the age of 18 and have a heritable mitochondrial condition

(due to changes in mitochondrial DNA) that affects their family.

Potential Risks or Discomforts

There are no risks identified as part of this survey. Although unanticipated, there may be emotional discomfort associated with discussing personal or family health topics.

The survey or interview can be terminated at any time by the participant.

Potential Benefits of the Research

Information arising from this study could be used to better medical care by communicating decision-making factors to the medical community, and could have an impact on legal decisions surrounding this therapy by making the opinions of the community of families affected by mitochondrial conditions known to policy-makers.

The information and experiences shared as a part of this study may also be useful to other families who may be considering this therapy in the future.

Confidentiality

Study information will be anonymized and kept secure. The only people who will have access to this raw data will be the primary researcher and those directly involved in this research. The researcher will keep your research data securely stored for three years after the completion of the initial research. If a scientific publication is created, all responses will be anonymized.

Costs

There is no cost to you beyond the time and effort required to complete the procedure(s) listed above.

Compensation

Compensation for participating in this research will be twenty dollars upon completion of the interview portion. There is no anticipated commercial profit related to this research.

Participation and Withdrawal

Your participation is voluntary. You may refuse to participate or stop participation at any time without penalty or loss of benefits.

Questions

If you have any questions about this research, you may contact me, Suzanna Tai, at [email protected] or my faculty sponsor, Janey Youngblom, at 209- 667-3950.

If you have any questions regarding your rights and participation as a research subject, please contact the IRB Administrator by phone (209) 667-3493 or email

[email protected].

Consent

Clicking the “Next” button below indicates that you are 18 years of age or older, and indicates your consent to participate in this survey. Please feel free to print a copy of this consent page to keep for your records.

1. What is your current age?

• Under 18

• 18 - 24

• 25 - 34

• 35 - 44

• 45 - 54

• 55 - 64

• 65 - 74

• 75 - 84

• 85 or older

2. What gender do you identify as?

• Male

• Female

• Other gender identity ______

3. What is your ethnicity (can choose multiple)?

• White

• Black or African American

• American Indian or Alaska Native

• Asian

• Native Hawaiian or Pacific Islander

• Other ______

• Decline to answer

4. In what region do you reside?

• Western United States

• Southwestern United States

• Midwestern United States

• Northeastern United States

• Southeastern United States

• Outside of United States - please specify country ______

5. What level of education have you attained?

• Some high school

• High school graduate

• Some undergraduate

• Undergraduate degree

• Graduate degree

• Doctorate or professional degree

6. Do you have biologic children?

• Have had one or more biologic children

• Planning to have biologic children within the next 5 years

• Planning to have biologic children in >5 years

• Not currently planning to have biologic children

7. Are you or is anyone in your family affected by a mitochondrial condition

(can select multiple)?

• Myself

• My child/children

• My grandchild

• My parent

• My sibling

• My aunt/uncle

• My cousin

• My grandparent

• Other (please specify) ______

"This procedure, called Mitochondrial Replacement Therapy, proposes to give women with mitochondrial DNA mutations an excellent chance of having a child that is over 99% genetically matched with her and her partner, and most importantly, is likely to be free of the mitochondrial disease." – United

Mitochondrial Disease Foundation

This therapy utilizes in vitro fertilization (IVF) and combines genetic information from both a donor egg and the intended parent’s egg. In this procedure, the nucleus containing DNA from the donor's egg is removed, and the recipient's nucleus will be placed into the donor’s egg. This results in a donor egg, with donor mitochondrial

DNA, that holds the nucleus from the recipient parent. The DNA contained in the nucleus contains the majority of the total DNA of the resulting egg. The egg can then be fertilized by sperm, and the resulting embryo can be transferred into the uterus of the recipient carrying the pregnancy.

The following link is from the Human Fertilisation and Embryology Authority in the

United Kingdom. It includes a brief description, FAQ, and further resources if you wish to learn more: https://www.hfea.gov.uk/treatments/embryo-testing-and- treatments-for-disease/mitochondrial-donation-treatment/

8. How would you rate your understanding of what the mitochondria do in the

body?

• Far below average

• Slightly below average

• Average

• Slightly above average

• Far above average

9. How would you rate your understanding of how mitochondrial DNA

conditions are inherited?

• Far below average

• Slightly below average

• Average

• Slightly above average

• Far above average

10. How would you rate your understanding of the variability of mitochondrial

conditions (i.e. range of severity)?

• Far below average

• Slightly below average

• Average

• Slightly above average

• Far above average

11. How would you rate your understanding of the difference between

mitochondrial DNA and nuclear DNA?

• Far below average

• Slightly below average

• Average

• Slightly above average

• Far above average

12. Do you believe that you are at risk to have a child with a mitochondrial

condition?

• Yes

• Maybe

• No

13. How would you rate your understanding of the process of mitochondrial

replacement therapy?

• Far below average

• Slightly below average

• Average

• Slightly above average

• Far above average

14. Before this survey, had you heard about mitochondrial replacement therapy?

• Yes

• No

Please note what times typically work well for you. I will reach out within four weeks of survey completion to arrange an interview time.

Morning (9AM- Afternoon (12PM - Evening (4PM -

12PM) 4PM) 8PM)

Monday ▢ ▢ ▢

Tuesday ▢ ▢ ▢

Wednesday ▢ ▢ ▢

Thursday ▢ ▢ ▢

Friday ▢ ▢ ▢

Saturday ▢ ▢ ▢

Sunday ▢ ▢ ▢

Please note preferred time zone. ______

APPENDIX C

INTERVIEW GUIDE

Thank you so much for taking the time to speak with me today. My name is

Suzanna, I’m a graduate student with California State University Stanislaus’ Genetic

Counseling Program. I’m conducting research as part of my program requirements, and I’m interested in the decision-making process about mitochondrial replacement therapy (MRT) from families who have experience with a mitochondrial disorder that runs in their family. My goal today is to ask some questions about how you heard about this therapy and your feelings about it. I’d like to take the opportunity now to let you know that I have no conflicts of interest involved in this research, thus I have no personal or financial stake in MRT.

Would you be comfortable with me recording this conversation so that I can accurately analyze it later? The recording will be deleted after it has been transcribed, and any identifying information will be removed.

You can decline to answer any questions, and we can end the interview early if you no longer want to continue. After we finish, your results will be anonymized and kept secure. The only people who will have access to this anonymized data will be myself and those directly involved with my research project. The goal of this study

71 is to learn more about the opinions of those who might consider or would have considered using mitochondrial replacement therapy on the therapy itself, and what their thought process is in coming to these opinions. The data I collect from these interviews may be used for a scientific paper, but all information will be de- identified. This interview will take about 30-60 minutes and you will be compensated for your time with $20. Do I have your consent to proceed?

This interview will have three sections. First, I’d like to understand your experience with mitochondrial disease and your current understanding of MRT. Then

I’d like to understand potential motivations and then reservations about a procedure like MRT.

Section I – Personal Knowledge and Experience

1. What is your experience with mitochondrial disease?

2. What is your knowledge of how the mitochondrial disease your family is affected

by is passed through the family?

3. Are there any reproductive options you’ve explored to change the chances of your

biological child might be affected by the mitochondrial disorder?

3.1. Yes – which?

4. How did you first hear about mitochondrial replacement therapy?

4.1. If outside (i.e. other than survey) - What did they tell you about it?

4.2. Has a medical professional ever discussed MRT with you?

5. Did you do any independent research after first hearing about MRT?

5.1. Yes - what kind?

5.1.1. What was found?

5.1.2. Have you read anything online about MRT that was confusing to you?

6. What is your current understanding of what MRT is?

7. Do you know how or if this therapy is currently available to you?

7.1. If no – discuss that this therapy is not currently legal in the US but has been

legalized in the UK. Then proceed to 7.3.

7.2. If yes – can you tell me your understanding of that? Then proceed to 7.3.

7.3. Would you consider trying this therapy in an alternative way?

7.3.1. If unsure what I mean - such as going to another country where it is

legal such as the UK, participating in a clinical trial, etc.?

8. How would you rate your knowledge about the therapy now from one to ten, one

being the not knowing anything to ten being knowing everything there is to know

about it?

9. Would you be interested in more information about MRT?

9.1. If yes – what kind of source would you prefer to hear this information from?

(i.e. online, physician, patient groups, other families, etc.)

10. What were your initial feelings about the therapy?

11. Have those feelings changed since?

12. Who do you turn to for support, particularly when issues related to your family’s

mitochondrial disease come up?

For the next two topics, I’d like you to consider your current feelings on mitochondrial replacement therapy, both your motivations and reservations. It’s okay if you’re not sure or have mixed feelings.

Section II - Motivations

1. What would be your motivations in pursuing this kind of therapy?

2. How does your own experience with mitochondrial disease affect the way you

view this therapy, if at all?

3. Do you have any personal thoughts or feelings about the mitochondrial condition

being hereditary?

3.1. If yes - What are they?

3.1.1. Do you envision a therapy like this changing that/those feeling(s)?

3.1.1.1. How so?

3.2. If no – Give examples (e.g. having a common experience, worry, discomfort

with ambiguity)

4. What is the best-case scenario you envision if you were to pursue this therapy?

4.1. How does that differ from what the situation would be if you didn’t pursue it?

5. Would the availability of this therapy change your consideration to have (more)

children?

5.1. For what reasons?

6. Are there any other factors I haven’t asked about that lead you to be interested in

this therapy for your own family?

7. How do you feel about the therapy being used for other reasons, such as

infertility?

Section III - Reservations

1. What reservations do you have about this therapy, if any?

1.1. Religious?

1.1.1. If yes – can you tell me more about that?

1.2. Ethical?

1.2.1. If yes – can you tell me more about that?

1.3. Moral?

1.3.1. If yes – can you tell me more about that?

2. What’s the worst-case scenario you envision for your family if you were to pursue

this therapy?

2.1. What aspect about that scenario worries you the most?

2.2. How do you think you might feel if the therapy wasn’t as effective as you’d

hoped?

3. A company in New York called DarwinLife, led by Dr. John Zhang, was involved

in the first baby being born following this therapy in Mexico. The therapy is not

approved by the FDA and is not available in the US but would involve the cost of

a cycle of in vitro fertilization in addition to the cost of the therapy itself. For

reference, a cycle of IVF alone can cost between $10,000 and $15,000. A

currently used therapy for couples that want to test embryos for a single gene

disorder in their nuclear DNA is called preimplantation diagnosis, and costs

approximately $4000 to $10000 – this gives us a rough idea of what we could

expect from mitochondrial replacement therapy, though PGD is a more

established procedure and is likely less expensive than what MRT would be. How

are those numbers sounding to you?

3.1. Not affordable - Would you be interested in utilizing the therapy if you could

afford it?

4. Do you have any other reasons surrounding why you might not consider

mitochondrial replacement therapy an option for your family?

Thank you so much for your time today, I really appreciate it. I will be sending you $20 via Google Pay through your email as a thank you for participating. I also have some additional information about MRT that I can send you if you’d like. Is that something you would be interested in?

Please don’t hesitate to contact me with any questions you may have. My email is [email protected], the same one that we used to communicate before this interview.

Have a nice day!