This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pediatrics
A 10-day-old male pseudohermaphrodite child with 46 XY karyotype presents with BP of 110/80 mm Hg. Most likely enzyme deficiency is: 
Select and explain. 
A. 21 hydroxylase, B. 17 hydroxylase, C. 11 hydroxylase, D. 3-beta hydroxylase
B: 17 hydroxylase
Answer: B: 17 hydroxylase 
Explanation: b. 17 hydroxylase(Ref: Nelson's 20/e p 2714-2423, Ghai 8/e p 526-527)In 17-hydroxylase deficiency: All pregnonolone is converted to mineralocorticoid. So, there will be:Excess of mineralocorticoids - Salt retention and hypertension.No androgens - Feminization of external male genitalia, while genitalia development will be normal in femalesComing back to this question, this neonate has: Hypertension (normal BP in a neonate =75/50) and male pseudohermaphroditism, both of which are features of 17-alpha hydroxylase deficiency.