<prompt> The enzyme defect in galactosemia isAldose reductaseGalactose-1-phosphate uridyltransferaseGalactokinaseAldolase B  <response>: Inability to metabolize galactose occurs in the galactosemias, which may be caused by inherited defects of galactokinase, uridyl transferase, or 4-epimerase Though deficiency of uridyl transferase is best known.Harper 30th edition pg: 205 