<prompt> Syndrome of apparent mineralocoicoid excess is due to deficiency of11a--hydroxysteroid dehydrogenase11b--hydroxysteroid dehydrogenase12a--hydroxysteroid dehydrogenase12b--hydroxysteroid dehydrogenase  <response>: Syndrome of apparent mineralocoicoid excess is due to genetic deficiency of 11b-dehydrogenase-2, cause hypokalemia. Liddles syndrome is caused by autosomal dominant gain-in-function mutations of ENaC subunits, cause hypokalemia. Loss of the transpo functions of the thick ascending loop of Henle and distal convoluted tubule nephron segments causes hereditary hypokalemic alkalosis, Baters syndrome BS and Gitelmans syndrome GS, respectively. Ref: Harrison 19e pg: 305 