Ambiguous external genitalia due to defect of 5-α-reductase in seven Iraqi patients: prevalence of a novel mutation

Abstract

We report on seven Iraqi patients with 46,XY karyotype and ambiguous genitalia characterized by perineo-scrotal hypospadias, bifid scrotum, clitoris like phallus, palpable testes in inguinal canal and pseudovagina. Patients were raised five as females and two as males. They are all unrelated with the exception of two couples of brothers. The diagnosis of 5-α-reductase-2 deficiency syndrome was first hypothesized on clinical grounds and then confirmed by molecular analysis. Direct sequencing analysis of the SRD5A2 gene revealed in five patients a novel homozygous frame-shift mutation (c.453delC) and in two related patients a previous reported missense mutation. The presence of the same mutation in unrelated patients of the same population suggests a possible founder effect. This report brings the 5-α-reductase-2 deficiency syndrome to the attention of clinical geneticists and child surgeons and discusses the appropriate clinical and surgical strategies for treating these patients.

Keywords: 46,XY DSD; 5-α-reductase type 2; AR; DHT; DSD; Founder effect; MRI; Phenotypic variability; SRD; SRD5A2; SRD5A2 gene; Steroid 5-α-reductase-2 deficiency; T; androgen receptor; dihydrotestosterone; hCG; human chorionic gonadotropin; magnetic resonance imaging; sex development disorder; steroid 5-α-reductase deficiency; testosterone.