To analyze the clinical characteristics of two patients with 3β-hydroxysteroid dehydrogenase deficiency and to explore their molecular genetic defects.

The clinical features and laboratory data of two patients were collected. The exons of HSD3B2 gene were amplified by PCR and sequenced by Sanger sequencing.

Patient 1, aged 5 yrs old, was raised as a girl with 46, XY karyotype, presented with hyperpigmentation, female infant vulva, clitoral hypertrophy, and bilateral cryptorchidism; Patient 2, aged 11 yrs old, was raised as a girl at birth but as a boy after 1 yr old for known 46, XY karyotype, presented with hyperpigmentation, micropenis and severe hypospadias. Both patients had markedly elevated adrenocorticotropin and decreased cortisol. Two homozygous missense mutations in HSD3B2 gene were identified: conversions of codon Pro¹⁵⁵ to Leu(p.P155L) in patient 1, and codon Ala⁸² to Thr(p.A82T) in patient 2, both of which were reported for the first time in China.

The patients with 3β-hydroxysteroid dehydrogenase deficiency in 46, XY karyotype mainly present with male pseudohermaphroditism and adrenocortical deficiency, and the diagnosis should rely on the steroids detection and HSD3B2 gene screening. (Chin J Endocrinol Metab, 2016, 32: 98-102)

3β-hydroxysteroid dehydrogenase deficiency; Congenital adrenal hyperplasia; Male pseudohermaphroditism; HSD3B2 gene