The most common cause of ambiguous genitalia in a newborn is -: (A) 21 hydroxylase deficinece, (B) 11 beta - hydroxylase deficiency, (C) 17 alpha - hydroxyalse deficiency, (D) 3 beta - hydroxysteroid deficiency
Answer is A. Ans. is 'a' i.e., 21 hydroxylase deficiency o Congenital adrenal hyperplasia due to classic 21-Hydroxylase deficiency is the most common cause of ambiguous genitalia in the newborn. Virilization is apparent at bih in the female and within the first 2-3 years of life in the male.