<prompt> classical type of galactosemia is due to deficiency of ?galactokinasealdose reductasegalactose 1-p uridyl transferasegalactose dehydrogenase  <response>: Galactosemia is due to deficiency of the enzyme galactose 1-phosphate uridyltransferase. It is a rare congenital disease in infants, inherited as autosomal recessive disorder. :Mutation in the GALT gene located on chromosome 9 is responsible for this disorder. 1. Galactose metabolism is impaired leading to increased galactose levels in blood galactosemia and urine galactosuria. 2. Accumulated galactose is diveed for production of galactitol by the enzyme aldol reductase. Galactitol has been implicated in the development of cataract. ref : lipincott 9th ed 