pediatrics
Congenital Adrenal Hyperplasia Caused by 21 Hydroxylase Deficiency
Nonclassic 21 hydroxylase deficiency
Nonclassic 21-hydroxylase deficiency is more common than classic 21-hydroxylase deficiency. Incidence ranges from 1/1000 to 1/2000 live births in White populations (0.1 to 0.2%) to 1 to 2% in certain ethnic groups (eg, Ashkenazi Jewish people). Nonclassic 21-hydroxylase deficiency causes a less severe form of the disorder in which there is 20 to 50% of 21-hydroxylase activity (compared to 0 to 5% activity in classic 21-hydroxylase deficiency). Salt wasting is absent because aldosterone and cortisol levels are normal; however, adrenal androgen levels are slightly elevated, resulting in mild androgen excess in childhood or adulthood. 