Pediatrics Most common cause of Congenital adrenal hyperplasia is deficiency of: A 17 alpha hydroxylase B 21 alpha hydroxylase C 11 beta Hydroxylase deficiency D 3 beta-HSD deficiency 💡 Explanation Most common cause of Congenital adrenal hyperplasia is deficiency of: ✓ Correct Answer: B. 21 alpha hydroxylase