[Adrenogenital syndrome. I. Introduction, enzymology and heredity].

The adrenogenital syndrome (AGS) is a relatively common inherited metabolic disease, generally caused by a deficiency of the adrenocortical enzyme steroid 21-hydroxylase. This results in an insufficient biosynthesis of several important steroid hormones such as cortisol and aldosterone, and, on the other hand, in a strongly increased production of androgens (testosterone). In girls, virilization of the external genitals is usually seen. In some patients, severe salt loss occurs shortly after birth, and a life-threatening crisis may develop. Mild variants of the disease have also been described. Steroid 21-hydroxylase is encoded by a gene within the HLA complex on the short arm of chromosome 6. HLA typing thus allows the study of the hereditary transmission of several forms of the AGS. In addition, molecular biology at present opens new perspectives to fundamental and clinical genetic research.