Enzyme deficient in Galactose, most commonly

Galactose is a substrate for aldose reductase, forming galactitol, which accumulates in the lens of the eye, causing cataract. The condition is more severe if it is the result of a defect in the uridyl transferase since galactose-1-phosphate accumulates and depletes the liver of inorganic phosphateUltimately, liver failure and mental deterioration result. In uridyl transferase deficiency, the epimerase is present in adequate amounts, so that the galactosemic individual can still form UDPGal from glucose.This explains how it is possible for normal growth and development of affected children to occur despite the galactose-free diets used to control the symptoms of the disease.Ref: Harper&;s Biochemistry 30th edition, page no: 205