Common Forms of Congenital Adrenal Hyperplasia

Congenital Adrenal Hyperplasia (CAH) was primarily caused by deficiencies in the enzymes 21-hydroxylase (CYP21) and 11-hydroxylase (CYP11B1), with the severity of enzyme deficiency ranging from complete to 40-50% of normal function. The clinical presentation depended on the degree of enzyme function loss. A total loss of 21-hydroxylase function led to cortisol and aldosterone deficiency, resulting in adrenal crisis or salt-wasting CAH, where females exhibited male-like external appearances due to androgen exposure. Simple virilising CAH presented in mid-childhood with rapid growth, increased body hair, and body odor, while non-classical CAH, or late-onset CAH (LOCAH), appeared in adolescence or adulthood with symptoms like excess body hair and irregular periods. In contrast, 11-hydroxylase deficiency resulted in salt retention and high blood pressure.