Investigating SOX9 regulation and FGF9 variants in Disorders of Sex Development

Disruption to genes required for normal testis development can result in Disorders of Sex Development (DSDs), which can lead to ambiguous genitalia, psychological issues, cancer and infertility. For most DSD patients, a genetic diagnosis cannot be provided, which severely compromises their clinical management. Using advanced genomic technologies together with cell culture-based and mouse modelling approaches, this study identified how two genes essential for mammalian testis development, SOX9 and FGF9, might function in humans. The study showed that mutations disrupting SOX9 and FGF9 function account for a significant proportion of genetically male DSD patients, thereby providing improved diagnosis and clinical management.