The most common enzymatic defect in congenital adrenal hyperplasia (adrenogenital syndrome) is:
A. 11-Hydroxylase deficiency
B. 17 – Hydroxylase deficiency
C. 21-Hydroxylase deficiency
D. 3-Beta dehydrogenase deficiency
Ans. C. 21, Hydroxylase deficiency is the
commonest enzyme defect (95%) in congenital adrenal hyperplasia. It is due to
impairment of CYP21A2 in addition to cortisol deficiency, aldosterone is also
low in about one third of patients. Adrenal virilization occurs with or without
a salt loosing tendency. Congenital adrenal hyperplasia is the commonest
adrenal disorder of infancy and childhood.
