Genetic Basis of Human Disorders of Gonadal Development PATRICK OPOKU MANU MAISON University of Cape Town A dissertation submitted in fulfillment of the requirements for the degree of Master of Science in Urology in the Faculty of Health Sciences, at the University of the Cape Town Cape Town, South Africa, 2017. i The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town Contents LIST OF TABLES .............................................................................................................................................. v LIST OF FIGURES ........................................................................................................................................... vi LIST OF ABBREVIATIONS ............................................................................................................................. vii DECLARATION: ........................................................................................................................................ ix ABSTRACT .................................................................................................................................................. x ACKNOWLEDGEMENT ..........................................................................................................................xiii CHAPTER ONE ........................................................................................................................................... 1 1.1 Rationale for the Study ........................................................................................................................... 1 CHAPTER TWO .......................................................................................................................................... 4 2.0. INTRODUCTION ................................................................................................................................. 4 2.1. Disorder of Sexual Differentiation ......................................................................................................... 4 2.1.1 Ovotesticular DSD ............................................................................................................................... 5 2.1.2. Classification of Ovotesticular DSDs ................................................................................................. 5 2.1.3. Clinical features of Ovotesticular DSD .............................................................................................. 6 2.1.3.2. The types of gonads ......................................................................................................................... 7 2.1.3.3 The distribution of gonads ................................................................................................................ 7 2.1.3.4 Distribution of karyotype .................................................................................................................. 9 2.1.3.5 External genitalia ............................................................................................................................ 10 2.1.4 Diagnosis............................................................................................................................................ 10 2.1.5 Sex of rearing ..................................................................................................................................... 11 2.1.6Management ........................................................................................................................................ 11 2.1.6.1 Surgical treatment ........................................................................................................................... 11 2.1.6.2 Sex Steroid Replacement .............................................................................................................. 12 2.1.6.3 Psychosocial management .............................................................................................................. 13 2.1.7 Prevalence of 46XX Ovotesticular DSD in South Africa .................................................................. 13 2.1.7.2. Familial incidence .......................................................................................................................... 14 2.2. The aetiology of 46XX Ovotesticular DSD ......................................................................................... 14 2.2.1. Normal fetal sex determination and gonadal differentiation ............................................................. 15 2.2.2. Chromosomal, gonadal and phenotypic sex ..................................................................................... 15 2.2.2. Gonadal differentiation and growth in Ovotesticular DSD ............................................................... 16 2.2.3 Mechanisms Underlying Testis Differentiation in SRY -Negative Individuals .................................. 17 ii SOX3 .......................................................................................................................................................... 18 DMRT1 ....................................................................................................................................................... 19 2.2.3.2 Insufficient Expression of Pro-Ovarian Genes ............................................................................... 19 WNT4 ......................................................................................................................................................... 19 RSPO1 ........................................................................................................................................................ 20 FOXL2 ........................................................................................................................................................ 20 2.3. Models for mammalian sex determination ........................................................................................... 21 2.3.1. The SOX model ................................................................................................................................ 21 2.3.2. The Z gene model ............................................................................................................................. 21 2.3.3. The DSS-gene model ........................................................................................................................ 22 2.3. 4 A proposed cascade for sex determination ....................................................................................... 22 2.4 A hypothesis on the molecular aetiology of Ovotesticular DSD ......................................................... 23 3.0 Materials and Methods .......................................................................................................................... 25 3.1 Study Site .............................................................................................................................................. 25 3.2 Study Participants ................................................................................................................................. 25 3.2. 1 Inclusion Criteria .............................................................................................................................. 25 3.2.2 Exclusion Criteria ............................................................................................................................ 25 3.3 Study Design ......................................................................................................................................... 25 3.4Sample/ Data Management: ................................................................................................................... 26 3.4.1 Massively parallel sequencing. .......................................................................................................... 26 3.4.2 Functional effects of mutations. ......................................................................................................... 27 3.5 Data Analysis ........................................................................................................................................ 30 3.6 Ethical and legal considerations ............................................................................................................ 35 CHAPTER FOUR ....................................................................................................................................... 36 4.0 RESULTS ............................................................................................................................................. 36 Clinical Findings ......................................................................................................................................... 36 Histologic Findings ..................................................................................................................................... 36 Gonadal Laterality and Distribution ........................................................................................................... 36 Laparoscopic Findings ...............................................................................................................................