5α-Reductase deficiency without hypospadias

Abstract

A boy aged 4 with penoscrotal hypospadias and his brother aged 12 with micropenis had typical changes of homozygous 5α-reductase deficiency. After three injections of chorionic gonadotrophin there was a trivial rise in plasma dihydrotestosterone with a normal increase in plasma testosterone. Urine steroid chromatography showed abnormally high 5β:5α ratios and 5α-reductase activity was appreciably reduced in genital skin fibroblasts. The results indicate that 5α-reductase deficiency is not invariably associated with genital ambiguity.