Clinical and genetic analysis of three Chinese patients with steroid 5α-reductase type 2 deficiency.

Steroid 5α-reductase type 2 deficiency (5α-RD2) is a rare autosomal recessive inherited disorder caused by mutations in the SRD5A2 gene. Its clinical features and pathogenesis in Chinese patients are poorly understood. This study aimed to characterize the clinical features and genetically analyze the SRD5A2 gene in three Chinese 5α-RD2 patients. The patients were characterized by ambiguous genitalia and spontaneous virilization without breast development at puberty. Elevated post-human chorionic gonadotropin stimulation T/DHT ratios were useful indicators of 5α-RD2 (with ratios of 20.4, 20.1, and 26.6 in the three patients, respectively). Two compound heterozygous mutations in the SRD5A2 gene were identified: p.G203S/p.R246Q in patients 1 and 2 and p.G203S/c.655delT in patient 3. The father and the mother of patients 1 and\xa02 were carriers of p.R246Q and p.G203S, respectively. p.G203S appears to be common in Chinese 5α-RD2 patients. Early genetic analysis should be performed in suspected patients to improve prognosis.