A 1–month old baby present with frequent vomiting and failure to thrive. There are features of moderate dehydration. Blood sodium in 122 mEq/1 and potassium is 6.1 mEq/1. The most likely diagnosis is –
High-Yield Explanation
Blood parameters indicate Hyponatremia and Hyperkalemia in this patient. All conditions other than 21 hydroxylase deficiency present with Hypokalemia.