What is Congenital adrenal hyperplasia?

A group of autosomal recessively inherited disorders associated with a deficiency of one of the enzymes involved in cortisol biosynthesis, resulting in elevation of ACTH levels and overproduction and accumulation of cortisol precursors proximal to the block; androgens are produced in excess, causing virilization. The most common disorder is the 21-hydroxylase deficiency, caused by mutation in the cytochrome P450 21-hydroxylase gene (CYP21) on chromosome 6p. There are three major types with some clinical similarities but distinctive genetic and biochemical differences: the salt-losing form [MIM*201710, MIM*201810, and MIM*202110]; the simple virilizing form [MIM*201910]; and the late onset form. All three forms are associated with abnormalities of the 21-hydroxylase gene.