Congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) resulting from 21-hydroxylase deficiency is the most common cause of ambiguous genitalia in the newborn. It is divided into the more severe classic and less severe nonclassic forms. Classic disease is characterized by genital ambiguity, occurs in 1 in 15,000 live births worldwide, and 75% of affected individuals also have concomitant mineralocorticoid deficiency, which can be fatal if not discovered. The remainder of the patients affected with the classic form of the disease exhibit virilization without mineralocorticoid deficiency. The nonclassic form of the disorder is present in 0.1-3% of populations and can be mistaken for idiopathic precocious pubarche in children or polycystic ovary syndrome in young women. This article presents an overview of the pathophysiology, diagnosis, and treatment of the various forms of CAH with 21-hydroxylase deficiency. An emphasis is placed on the recommendations made recently by the Joint Lawson Wilkins Pediatric Endocrinology Society/European Society for Pediatric Endocrinology CAH Working Group in their consensus statement published in September 2002.(1)