pediatrics
Congenital Adrenal Hyperplasia Caused by 21 Hydroxylase Deficiency
Classic 21 hydroxylase deficiency
Classic 21-hydroxylase deficiency can be divided into 2 forms: Salt wasting Simple virilizing In both forms, adrenal androgen levels are elevated, causing virilization. Thesalt-wasting formis the most severe and accounts for 70% of classic 21-hydroxylase deficiency cases; there is complete deficiency of enzyme activity that leads to very low levels of cortisol and aldosterone. Because minimal aldosterone is secreted, salt is lost, leading to hyponatremia, hyperkalemia, and increased plasma renin activity. In thesimple virilizing form,cortisol synthesis is impaired, leading to increased androgen activity, but there is sufficient enzyme activity to maintain normal, or only slightly decreased, aldosterone production. 