5 alpha-reductase deficiency without hypospadias.
 A boy aged 4 with penoscrotal hypospadias and his brother aged 12 with micropenis had typical changes of homozygous 5 alpha-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 5 beta: 5 alpha ratios and 5 alpha-reductase activity was appreciably reduced in genital skin fibroblasts.
 The results indicate that 5 alpha-reductase deficiency is not invariably associated with genital ambiguity.
