[Congenital adrenal hyperplasia].

Introduction: Congenital adrenal hyperplasia (CAH) comprises a group of autosomal recessive disorders, which are due to defects in single enzymes involved in adrenal steroidogenesis. The biochemical and clinical phenotype depends on the specific enzymatic defect. In 21hydroxylase and 11β-hydroxylase deficiency only adrenal steroidogenesis is affected, whereas a defect in 3β-hydroxysteroid dehydrogenase or 17α-hydroxylase also involves gonadal steroid biosynthesis. Recently, a novel form of CAH has been identified that is caused by mutations in P450 oxidoreductase, the electron donor enzyme for 21-hydroxylase and 17α-hydroxylase. Steroid 21-hydroxylase deficiency will be the main focus of this presentation as it accounts for about 95% of cases.