Commonest cause of congenital adrenal hyperplasia is

(21 hydroxylase) (489-90-G) (492-Ghai 7th)* 21 hydroxylase & 11-b hydroxylase deficiency are common varieties21 hydroxylase11-b hydroxylase deficiency* May present as salt-wasting form of CAH, due to the associated aldosterone deficiency resulting in life threatening emergencies in the early postnatal life* These may present with severe vomiting and vascular collapse* Boys with CAH do not have anomaly of the external genitals at birth* Results in accumulation of deoxycortisol (DOC) because enzymatic block is beyond this stage* These children develop hypertension of varying severity due to excessive DOC