CYP21A2 and congenital adrenal hyperplasia: The classic CAH, showing a prevalence of 1:16,000 live births in the Caucasian population, is in turn classified into two forms on the basis of disease severity: the salt-wasting (SW), associated with CYP21A2 variants removing enzyme activity, with deficiency of cortisol and aldosterone, and the simple virilizing (SV), associated with CYP21A2 variants retaining <5% of enzyme activity, with ability to synthetize aldosterone.