A 10 day old male pseudohermaphrodite child with 46 XY karyotype presents with BP of 110/80 mmHg. Most likely enzyme deficiency is -

Ans. is 'b' i.e., 17 a hydroxylase To understand the pathophysiology and effects of different congenital adrenal hyperplasia, one should know the synthetic pathway of steroid hormones. Steroidogenesis o All steroid hormones are synthesized from precursor pregnenolone which inturn is derived from cholesterol. 1. 17-alpha hydroxylase deficiency All pregnonolone is conveed to mineralocoicoid, pathway. So, there will be : - i) Excess of mineralocoicoids Salt retention & hypeension ii) No androgens --> Faminization of external male genitalia (male pseudohermaphroditism). Female development will be normal. 2. 11-(3 hydroxylase deficiency Cycle will go upto deoxycoicosterone and deoxycoisole. So, there will be : ? i) Excess deoxycoicosterone ----> It has mineralocoicoid activity which results in hypeension. ii) Excess androgen Virilization of female (female pseudohermaphroditism). In males, there will precocious pubey due to excess of androgens. 3. 21 hydroxylase deficiency Cycle will go upto progesterone So, there will be i) Deficiency of mineralocoicoid --> Salt losing - hypotension, hyponatremia, low chloride, hyperkalemia. ii) Deficiency of coisol (glucocoicoids): Hypoglycemia, hyperpigmentation (due to excess ACTH) iii) Excess androgens --> Virilization of female (female psueohermaphroditism). In males, there will be precocious pubey due to excess of androgens.