Genetic Variants in SRD5A2 in a Spectrum of DSD Patients from Australian Clinics Highlight Importance of Genetic Testing alongside Typical First-Line Investigations

Abstract

Introduction: Steroid 5-alpha reductase deficiency (5α-R2D) is a rare condition caused by genetic variants that reduce the activity of the enzyme that converts testosterone into dihydrotestosterone. The clinical spectrum of 5α-R2D is known to overlap with other 46,XY differences of sex development (DSD) such as androgen insensitivity or gonadal dysgenesis. However, the clinical trajectories of the aetiologies can differ, with 5α-R2D presenting its own challenges. Methods: In this study, we have collated clinical information for five individuals with variants in SRD5A2 identified using research genetic testing in an Australian paediatric setting. Results: We describe how a genetic finding resolved or confirmed a diagnosis for these individuals and how it guided clinical management and family counselling. Conclusion: This work highlights the importance of early genetic testing in children born with 46,XY DSD where it complements traditional first-line testing.