In congenital adrenal hyperplasia, mutations in the CYP21A2 gene can cause varying degrees of 21-hydroxylase activity loss leading to a range of phenotypes (from androgen excess for the milder form to virilization or “salt-wasting” with cortisol and mineralocorticoid deficiency for the most severe) [9]. Here, CYP21A2 is linked to congenital adrenal hyperplasia.