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Year: 2019
Double variants in TSHR and DUOX2 in a patient with hypothyroidism: case report
Sasivari, Zerin ; Szinnai, Gabor ; Seebauer, Britta ; Konrad, Daniel ; Lang-Muritano, Mariarosaria
Abstract: Thyroid dyshormonogenesis (TDH) is characterized by the defective synthesis of thyroid hor- mones. We present a patient with congenital hypothyroidism (CH) who presented in newborn screening with elevated serum thyroid-stimulating hormone (TSH), decreased free thyroxine (fT
DOI: https://doi.org/10.1515/jpem-2019-0051
Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-178432 Journal Article Published Version
Originally published at: Sasivari, Zerin; Szinnai, Gabor; Seebauer, Britta; Konrad, Daniel; Lang-Muritano, Mariarosaria (2019). Double variants in TSHR and DUOX2 in a patient with hypothyroidism: case report. Journal of Pediatric Endocrinology Metabolism, 32(11):1299-1303. DOI: https://doi.org/10.1515/jpem-2019-0051 J Pediatr Endocrinol Metab 2019; 32(11): 1299–1303
Case Report
Zerin Sasivari, Gabor Szinnai, Britta Seebauer, Daniel Konrad and Mariarosaria Lang-Muritano* Double variants in TSHR and DUOX2 in a patient with hypothyroidism: case report https://doi.org/10.1515/jpem-2019-0051 Received February 27, 2019; accepted August 12, 2019; previously Introduction published online September 21, 2019 Congenital hypothyroidism (CH) occurs with an incidence Abstract: Thyroid dyshormonogenesis (TDH) is charac- of 1:3000–1:4000 [1]. Neonatal screening for CH was intro- terized by the defective synthesis of thyroid hormones. duced in Switzerland in 1977 to prevent mental retardation We present a patient with congenital hypothyroidism in affected newborns [2]. Newborn screening in Swit- (CH) who presented in newborn screening with elevated zerland determines thyroid-stimulating hormone (TSH) serum thyroid-stimulating hormone (TSH), decreased free but not thyroxine (T4) concentration. Thus, newborns thyroxine (fT4) and increased thyroglobulin (Tg) concen- with central or secondary hypothyroidism are missed in trations. Ultrasound scan revealed a properly structured Switzerland. thyroid gland. Treatment with L-thyroxine was initiated. Primary CH can be classified into two forms: thyroid At the age of 2 years, thyroxine replacement was stopped. dysgenesis, which accounts for approximately 80–85% of The patient remained untreated until 6 years of age when all cases with permanent primary CH including resistance TSH levels progressively increased and L-thyroxine treat- to TSH, and thyroid dyshormonogenesis (TDH), account- ment was restarted at a dose of 12.5 µg/day. Genetic ing for 10–15% of cases. Thyroid dysgenesis is caused by analysis revealed a double heterozygosity for likely path- disordered development of the thyroid gland and results ogenic variants of dual oxidase 2 (DUOX2) and thyroid in athyreosis, hypoplastic or ectopic thyroid gland. TSH stimulating hormone receptor (TSHR). Both genes were resistance can cause hypoplastic or normally sized thyroid earlier shown to be associated with CH. In a literature gland. TDH is characterized by eutopic thyroid gland of review, our patient was compared to previously published normal size, or goiter [1]. patients with similar clinical characteristics, and a good Most forms of TDH are transmitted autosomal reces- genotype-phenotype correlation was identified. sively and so far variants in seven different genes coding for the following proteins have been identified: thyroid Keywords: congenital hypothyroidism; DUOX2 variant; peroxidase (TPO), thyroglobulin (TG), pendrin (causing TSHR variant. Pendred syndrome [SLC26A4/PDS]), sodium iodide trans- porter (SLC5A5/NIS), dual oxidase 2 (DUOX2), dual oxidase maturation factor (DUOXA2) and iodotyrosine deiodinase (IYD) [3]. *Corresponding author: Mariarosaria Lang-Muritano, MD, DUOX2 Department of Paediatric Endocrinology and Diabetology, University is a transmembrane protein. It generates H2O2, Children’s Hospital, Steinwiesstrasse 75, CH-8032 Zurich, which is required for the synthesis of thyroid hormones. Switzerland; and Children’s Research Centre, University Children’s Variants in the DUOX2 gene may result in transient or per- Hospital, Zurich, Switzerland, Phone: +41 44 266 72 73, manent dyshormonogenesis [3]. E-mail: [email protected] The TSH receptor (TSHR) gene codes for the TSH- Zerin Sasivari: Department of Paediatric Endocrinology and Diabetology, University Children’s Hospital, Zurich, Switzerland receptor, which is a transmembrane protein binding Gabor Szinnai: Department of Paediatric Endocrinology and TSH and consequently stimulating thyroid hormone Diabetology, University Children’s Hospital, Basel, Switzerland production. Its variant causes TSH resistance resulting Britta Seebauer: Department of Medical Genetics, University in increased TSH levels in an effort to maintain normal Hospital Basel, University of Basel, Basel, Switzerland thyroid hormone secretion, which is not always achieva- Daniel Konrad: Department of Paediatric Endocrinology and TSHR Diabetology, University Children’s Hospital, Zurich, Switzerland; ble. pathogenic variants cause variable phenotypes, and Children’s Research Centre, University Children’s Hospital, ranging from asymptomatic to severe hyper or hypo- Zurich, Switzerland thyroidism. Carriers of inactivating biallelic TSHR gene
Bereitgestellt von | provisional account Unangemeldet Heruntergeladen am | 09.01.20 10:00 1300 Sasivari et al.: Dyshormonogenesis due to double variants variants are likely to be identified by neonatal screening, substitution 4 weeks earlier. Scintigraphy with 4MBq whereas those with autosomal dominant-inherited mono- 123Jcd revealed homogenous accumulation of the radio- allelic variants appear in milder forms and may be missed nuclide in a correctly located thyroid gland. in the screening [4, 5]. After discontinuation of thyroid hormone replace- Herein, we present a boy with mild CH due to double ment, TSH concentration increased and remained slightly TSHR DUOX2 variants in the and gene. elevated (Figure 1), whereas fT4 was always within normal limits. At this time, the patient showed no symptoms. Therefore, therapy was not restarted as subclinical hypo- Case report thyroidism should not be treated unless there are signs or symptoms of hypothyroidism [6]. The patient remained untreated until the age of The patient was born of non-consanguineous parents 6 years when complaints of fatigue and dry skin appeared. at term, his body weight was 3370 g (P50), and his birth At presentation, the patient was clinically examined and length was 50 cm (P50). Pregnancy and spontaneous showed no signs of infection, so no blood test for infec- vaginal delivery were uneventful. In the newborn screen- tion parameters was done. As a differential diagnosis for ing on the 10th postnatal day, serum TSH concentration fatigue, serology tests for celiac disease were done with was elevated (79.1 mU/L [normal range: 0.1–10.5]). In the negative results. recall test after a few days, the TSH level was 222 mU/L and As TSH levels were also increasing, L-thyroxine free thyroxine (fT ) was decreased (0.27 ng/dL [0.8–2.31]). 4 replacement was restarted with a dose of 12.5 µg/day. At Thyroglobulin (Tg) was massively increased (980 µg/mL the time of treatment reinstitution, the patient’s height [<75 µg/mL]). At this point, treatment with L-thyroxine was 119.4 cm (P 50, +0.05 standard deviation [SD]), was started with a dose of 25 µg/day. Five days later, weight was 24.5 kg (P 75, +0.84 SD) and body mass index the dose was increased to 50 µg/day. Further evaluation (BMI) was 17.2 kg/m2 (P 75–90; z-score +1.2 SD). Thus, the revealed thyroid peroxidase, Tg and TSH receptor antibod- patient was not overweight. ies within the normal range. Ultrasound was performed During follow-up, TSH levels remained stable within during a follow-up visit 4 weeks after birth, showing a the normal range, fatigue disappeared and L-thyroxine homogenous thyroid gland loco classico with a longitudi- therapy was continued with a dose of 25 µg/day until nal dimension of 15 mm and each lobe having a width of adulthood when the patient was transitioned to adult 7 mm. Family history was unremarkable for thyroid prob- endocrinology. lems except for the maternal grandmother, who devel- oped hypothyroidism after menopause. All these findings suggested a likely diagnosis of TDH. A perchlorate test to Materials and methods distinguish from a thyroid dysgenesis was not performed. At the age of 2 years, the patient’s thyroid function To analyze the patient’s DNA, a custom-designed Illumina sequenc- was reevaluated after cessation of L-thyroxine (50 µg) ing panel containing genes involved in thyroid dysgenesis (FOXE1,
Start of therapy End of therapy Restart of therapy 250 8 25 µg L- 12.5 µg L-thyroxine, daily thyroxine, 7 200 daily 6 25 g L-thyroxine, End of therapy µ 5 daily 150 50 µg L- 4 thyroxine, 100 daily 3 TSH level, mU/L TSH level, mU/L 2 50 End of 1 therapy 0 0 2.26 2.33 2.36 2.41 2.45 2.56 2.83 3.38 3.47 3.97 4.62 5.49 6.54 6.98 9.91 11.25 0.7 0.03 0.04 0.06 0.08 0.12 0.21 0.39 0.97 1.47 2.26 Age, years Age, years
Figure 1: Course of TSH concentration over time. The dose per kilogram of L-thyroxine on the first episode of therapy ranged from 3 µg/kg to 10 µg/kg. At restart of therapy, the dose was approximately 0.3–0.5 µg/kg/day. Current dose is 0.37 µg/kg/day.
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NKX2-1, NKX2-5, PAX8 and TSHR) and dyshormonogenesis (DUOX2, of fatigue disappeared after retreatment. Therefore, it DUOXA2, IYD, SLC5A5/NIS, SLC26A4/PDS, TG and TPO) was used. is difficult to definitively settle whether our patient had Library preparation was performed according to the standard pro- transient hypothyroidism. tocol (Nextera rapid capture custom enrichment kit, Illumina, San Diego, CA, USA), followed by sequencing on the MiSeq sequenc- CH has recently been shown to occur not only as ing platform (Illumina, San Diego, CA, USA). Sequencing data were monogenic but also as an oligogenic disease, especially analyzed using the software Variant Studio (Illumina, San Diego, CA, in patients with eutopic thyroid gland [11]. Our patient USA) and SequencePilot (JSI medical systems, Ettenheim, Germany). carries two gene variants, one in the TSHR gene and one Variants of interest were confirmed by Sanger sequencing. in the DUOX2 gene, both being previously associated with CH. If only one of these genes is mutated, reported pheno- Ethical statement types are variable and also depend on whether both or one allele is affected. If only one allele is mutated, symptoms Informed consent was obtained from all individuals included in are usually mild and hypothyroidism may be transient or this study. The research related to human use complied with all the mild. Such an observation has been made for both, DUOX2 relevant national regulations and institutional policies, and was in variants [12] and TSHR variants [5, 13]. However, correla- accordance with the tenets of the Helsinki Declaration, and has been tion between genotypes and phenotypes may be more approved by the authors’ Institutional Review Board or equivalent committee. complex as biallelic DUOX2 variants also presented with only moderate clinical signs of hypothyroidism. In the literature, 10 cases with double heterozygous Results variants of the TSHR and DUOX2 genes similar to our patient have been reported with available clinical data and are reviewed in Table 1 [4, 13–15]. Additional cases The patient is heterozygous for two variants in the genes with double mutations have been published but are not DUOX2 and TSHR with a known phenotype of TDH. In included in the table as clinical data were not available DUOX2, the sequence variant c.602dupG was identified. [16–19]. One base pair is duplicated with the molecular conse- The presence of an additional monoallelic DUOX2 quence of a frameshift (p.[Gln202ThrfsTer99]). In the variant in a newborn with a monoallelic TSHR variant ClinVar database, it is described as pathogenic/likely makes a positive result in the newborn TSH screening 10 pathogenic for dyshormonogenesis [7, 8]. times more probable compared to carriers with a TSHR In the exon 1 of the TSHR gene, the sequence variant variant alone. Along this line, the frequency of double c.122G > C has been identified. A guanine replaces cysteine heterozygosity in patients with CH was reported to be which results in an amino acid exchange from cysteine to much higher than in the general population in Japan [4]. serine (p.[Cys41Ser]). This variant is asserted to be patho- Accordingly, only three out of 11 patients presented in genic for CH [9]. Table 1 revealed no or only slightly elevated TSH values In both the genes, there was no evidence of a second in the confirmative blood sample after newborn screening pathogenic sequence variant. No gene dose analysis was (upper cutoff value of 10.5 mU/L). All other cases showed implemented. The patient is a heterozygous carrier of the strongly elevated TSH values and very low fT levels, DUOX2 sequence variant associated with mild hypothy- 4 resulting in immediate L-thyroxine replacement. Only four roidism and the TSHR sequence variant associated with of the latter patients had to continue thyroxine therapy a TSH resistance. after re-evaluation, whereas the other four showed stable TSH levels in the upper range, similar to our patient. Thus, the genotype alone does not seem to predict the clinical Discussion follow-up and the need for replacement therapy. Thyroid size was reduced in the majority of reviewed According to the consensus guidelines of the European patients fitting more to TSHR sequence variants than to Society for Paediatric Endocrinology, transient hypothy- DUOX2 variants. Unfortunately, TG concentration was roidism is defined as elevated TSH levels in the first days reported in only one of the reviewed patients. Like in our of a newborn with normalized values after a period of no patient, it was increased. It would be interesting to know treatment [10]. After the off-treatment period, the patient whether Tg concentration was also elevated in the other had increased TSH values slightly over the range which patients. would fit the definition of transient hypothyroidism. Yet Watching the variations, it seems that p.R450H in our patient needed a restart of therapy, and the symptoms TSHR is a frequent variant in combination with a DUOX2
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variant. But this TSHR allele variant has also been dem- onstrated to be a common variant in the Japanese and a
a Taiwanese population, independent of an additional pathogenic variant [13]. + + 222 Normal 980 16 days 79.1 3.2 2 years 3 months 2 years Male 0.32 Our patient Our p.Q202Tfs p.C41S In conclusion, our data demonstrate higher probabil-
ity for CH in patients with double heterozygosity for TSHR c,d c and DUOX2. However, the necessity of continuous thyroid replacement is difficult to predict despite good genotype- 100 + + > Normal NA NA NA NA NA Female 0.27 Case 10 [13] Case p.E879K p.F696C
phenotype correlation. a a 100 + + > Normal NA NA NA NA NA 0.69 Case 9 [13] Case p.K530X p.R109Q Established facts and learning
a c points 100 – + > Enlarged NA NA NA NA NA Male Male 0.37 Case 8 [13] Case p.K530X p.Y613C Established facts
c a – Carriers of inactivating biallelic TSHR gene vari- ants are likely to be identified by neonatal screen- ing, whereas those with monoallelic variants may be – + 164.5 Decreased 60 days NA 13.6 9 6 years Female 1.2 Case 7 [4] Case p.V779M p.R450H
a
a missed in the screening [4, 5]. – DUOX2 pathogenic variants can cause transient or permanent hypothyroidism [12]. – + 85.3 Normal NA NA 3.3 NA 3 years NA Case 6 [4] Case p.K530X p.R450H
– The coexistence of DUOX2 and TSHR variants leads to a a a higher probability of CH [4]. ) compared to our patient. our to ) compared TSHR – – 4.9 Decreased 40 days NA 1.4–7.2 14 NA Male Male NA Case 5 [4] Case p.K530X p.R450H Learning points
and and
a – We report the first case with this combination of path- c ogenic variants of DUOX2 and TSHR with long-term DUOX2 Described as pathogenic in the study [8]. NA, not available, reference values: TSH (at screening): screening): (at TSH values: reference available, [8]. NA, not in the study pathogenic as Described d clinical follow-up. – – 14.1 Decreased NA NA NA NA NA Female In the range Case 4 [4] Case p.E327X p.R450H
c – Patients with variants of TSHR and DUOX2 show dif- g/mL. Reference values according to the University Children’s Hospital, Zurich, Switzerland. Each laboratory laboratory Each Switzerland. Zurich, Hospital, Children’s the University to according values g/mL. Reference µ ferences in phenotype despite the same genotype. 75 < /p.L1343F c
a Author contributions: Sasivari Z analyzed the patient’s dossier and wrote the paper. Seebauer B is responsible for genetic investigation. Szinnai G, Konrad D and Seebauer + + 10.51 Normal NA 1 year 8 months 1 year 4.1 21.18 2 years 10 months 2 years Male 0.88 Case 3 [15] Case p.A1323T p.R450H
B provided critical feedback and helped shape the manu- c a script. Lang-Muritano M treated the patient from birth and : 0.8–2.31 ng/dL, Tg: Tg: ng/dL, : 0.8–2.31 4 was the supervisor of this paper. + + 35 Normal NA 14 days 41.7 41 3 years Female 1 Case 2 [14] Case p.A1123T p.R450H Research funding: None declared.
a b Employment or leadership: None declared. Clinical significance not reported in ClinVar, in ClinVar, reported not significance Clinical c Honorarium: None declared. Competing interest: The authors declare that they have no p.H678R NA + 91.2 Normal 231 20 days NA 7.2 3 years Male 0.57 Case 1 [14] Case p.G132R
Benign. conflict of interest. b
References
1. Rastogi MV, LaFranchi SH. Congenital hypothyroidism. Orphanet J Rare Dis 2010;5:17. Clinical and molecular characteristics of reported cases with double variants ( variants double with cases reported of characteristics molecular and Clinical variant , ng/dL (at conf. diagnosis) conf. (at ng/dL , 2. Illig R, Largo RH, Qin Q, Torresani T, Rochiccioli P, et al. Mental 4 variant g/mL at diagnosis at g/mL
µ development in congenital hypothyroidism after neonatal screen- Pathogenic/likely pathogenic. pathogenic. Pathogenic/likely DUOX2 Treatment in childhood Treatment Free T Free in infancy Treatment Thyroid size TSH, mU/L (at conf. diagnosis) conf. (at mU/L TSH, Age at confirmative diagnosis confirmative at Age Tg, TSH, mU/L (at re-evaluation) (at mU/L TSH, TSH, mU/L (at screening) (at mU/L TSH, Age at re-evaluation at Age has specific reference ranges. Tg, thyroglobulin; TSH, thyroid-stimulating hormone. thyroid-stimulating TSH, thyroglobulin; Tg, ranges. reference specific has a TSHR Table 1: Table Sex 0.1–10.5 mU/L, TSH (re-evaluation): 0.1–3.7 mU/L, fT 0.1–3.7 mU/L, (re-evaluation): TSH 0.1–10.5 mU/L, ing. Arch Dis Child 1987;62:1050–5.
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3. Szinnai G. Clinical genetics of congenital hypothyroidism. 12. Fu C, Luo S, Zhang S, Wang J, Zheng H, et al. Next-generation Endocr Dev 2014;26:60–78. sequencing analysis of DUOX2 in 192 Chinese subclinical 4. Abe K, Narumi S, Suwanai AS, Adachi M, Muroya K, et al. Asso- congenital hypothyroidism (SCH) and CH patients. Clin Chim ciation between monoallelic. Eur J Endocrinol 2018;178:137–44. Acta 2016;458:30–4. 5. Persani L, Calebiro D, Cordella D, Weber G, Gelmini G, et al. 13. Fu C, Wang J, Luo S, Yang Q, Li Q, et al. Next-generation Genetics and phenomics of hypothyroidism due to TSH resist- sequencing analysis of TSHR in 384 Chinese subclinical con- ance. Mol Cell Endocrinol 2010;322:72–82. genital hypothyroidism (CH) and CH patients. Clin Chim Acta 6. Salerno M, Capalbo D, Cerbone M, De Luca F. Subclinical hypo- 2016;462:127–32. thyroidism in childhood – current knowledge and open issues. 14. Jin HY, Heo SH, Kim YM, Kim GH, Choi JH, et al. High frequency Nat Rev Endocrinol 2016;12:734–46. of DUOX2 mutations in transient or permanent congenital 7. Pfarr N, Korsch E, Kaspers S, Herbst A, Stach A, et al. Congenital hypothyroidism with eutopic thyroid glands. Horm Res Paediatr hypothyroidism caused by new mutations in the thyroid oxidase 2014;82:252–60. 2 (THOX2) gene. Clin Endocrinol (Oxf) 2006;65:810–5. 15. Satoh M, Aso K, Ogikubo S, Yoshizawa-Ogasawara A, Saji T. 8. Muzza M, Rabbiosi S, Vigone MC, Zamproni I, Cirello V, et al. Hypothyroidism caused by the combination of two The clinical and molecular characterization of patients with heterozygous mutations: one in the TSH receptor gene the dyshormonogenic congenital hypothyroidism reveals specific other in the DUOX2 gene. J Pediatr Endocrinol Metab diagnostic clues for DUOX2 defects. J Clin Endocrinol Metab 2015;28:657–61. 2014;99:E544–53. 16. de Filippis T, Gelmini G, Paraboschi E, Vigone MC, Di Frenna M, 9. Alberti L, Proverbio MC, Costagliola S, Romoli R, Boldrighini et al. A frequent oligogenic involvement in congenital hypothy- B, et al. Germline mutations of TSH receptor gene as cause of roidism. Hum Mol Genet 2017;26:2507–14. nonautoimmune subclinical hypothyroidism. J Clin Endocrinol 17. Park KJ, Park HK, Kim YJ, Lee KR, Park JH, et al. DUOX2 mutations Metab 2002;87:2549–55. are frequently associated with congenital hypothyroidism in the 10. Léger J, Olivieri A, Donaldson M, Torresani T, Krude H, et al. Korean population. Ann Lab Med 2016;36:145–53. European Society for Paediatric Endocrinology consensus guide- 18. Sun F, Zhang JX, Yang CY, Gao GQ, Zhu WB, et al. The genetic lines on screening, diagnosis, and management of congenital characteristics of congenital hypothyroidism in China by com- hypothyroidism. Horm Res Paediatr 2014;81:80–103. prehensive screening of 21 candidate genes. Eur J Endocrinol 11. Nicholas AK, Serra EG, Cangul H, Alyaarubi S, Ullah I, et al. 2018;178:623–33. Comprehensive screening of eight known causative genes in 19. Fan X, Fu C, Shen Y, Li C, Luo S, et al. Next-generation sequenc- congenital hypothyroidism with gland-in-situ. J Clin Endocrinol ing analysis of twelve known causative genes in congenital Metab 2016;101:4521–31. hypothyroidism. Clin Chim Acta 2017;468:76–80.
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