<prompt> A 2-year-old child presented with diarrhoea and failure to thrive, Blood examination shows Na 122,K 6. He is most probably suffering fromBanter syndrome21α Hydroxylase deficiency11β Hydroxylase deficiency17a Hydroxylase deficiency  <response>: Na is 122 hyponatremia. That means, there is salt losing enzyme deficiency, causing hyponatremia and hyperkalemia.21 hydroxylase deficiency causes hyponatremia and hyperkalemia. 17α -hydroxylase and 11-β - hydroxylase deficiency cause hypernatremia and hypokalemia.Butter syndrome causes excessive loss of Na, K and Cl causing severe hypokalemia and hyponatremia. 