A Novel Mutation of the Steroid 5-Alpha Reductase Type 2 (SRD5A2) Gene in a Korean Newborn with Ambiguous Genitalia / 대한소아내분비학회지

ABSTRACT

The term "disorders of sex development" (DSD) includes congenital conditions in which development of chromosomal, gonadal or anatomical sex is atypical. Steroid 5-alpha reductase type 2 deficiency (5alpha-RD2) is an uncommon autosomal recessive disorder of sexual differentiation. It results from impaired conversion of testosterone (T) to dihydrotestosterone (DHT) due to mutations in the steroid 5-alpha reductase type 2 (SRD5A2) gene. It is characterized by a lack of masculinization in XY individuals due to failure to convert testosterone to dihydrotestosterone. More than 40 mutations have been reported in all five exons of the SRD5A2 gene. Here, we report on a 17-day-old Korean newborn who was confirmed to have 5alpha-RD2 by SRD5A2 gene analysis. He manifested micropenis, hypospadia and bilateral cryptorchidism without skin hyperpigmentation. T/DHT ratio after human chorionic gonadotropin (hCG) stimulation was slightly increased and genetic analysis of SRD5A2 revealed compound heterozygous mutations, c.657C > G (p.Phe219Leu) and c.656del (p.Phe219SerfsX60), the former of which is a novel mutation. We report a novel SRD5A2 gene mutation in a Korean newborn with 5alpha-RD2.