Autosomally dominantly inherited isolated gonadotropin deficiency via maternal assisted reproduction due to SOX10 mutation

Background: Kallmann syndrome (KS) is a rare genetic disorder marked by hypogonadotropic hypogonadism and either anosmia or hyposmia. It exhibits genetic heterogeneity, with mutations identified in only 30 % of cases, involving various genes such as KAL1, FGFR1, FGF8, CHD7, and SOX10. Here, we present a case of gonadotropin deficiency associated with KS, observed in both a mother and her daughter, the latter conceived through assisted reproductive technology using the mother's ovum.

Case summary: A 12-year-old female presented with short stature and lack of growth over the past year. Initial laboratory testing revealed mildly elevated TSH (8.348 uIU/mL), normal free T4 (0.9 ng/dL), and positive thyroid antibodies, including elevated TPO (629 IU/mL). Her growth hormone peak response to stimulation testing was 12.8 ng/mL, and GnRH stimulation indicated a peak LH value of 1.78 mIU/mL and a peak FSH value of 2.83 mIU/mL, consistent with hypogonadotropic hypogonadism (HH). Genetic testing identified a novel heterozygous variant in the SOX10 gene, predicted to be damaging, and also present in her mother, who had Kallmann syndrome. The patient was initiated on low-dose estrogen therapy with estradiol patches to stimulate growth and pubertal development.

Conclusions: This case highlights the transmission of a novel SOX10 mutation in a mother-daughter pair through assisted reproductive technology, bypassing the typical infertility-related barriers to genetic inheritance in KS. The autosomal dominant inheritance pattern observed in this family emphasizes the importance of genetic counseling when reproductive assistance is considered. This case also suggests that SOX10 mutations may contribute more broadly to the pathogenesis of KS and related HH.