Cataracts in Galactosaemia

Abstract

WHEN milk is taken by mouth, the lactose that it contains (breast milk contains a higher concentration than cow's milk) is hydrolysed by the enzyme lactase into its constituent monosaccharides, glucose and galactose, which are absorbed from the intestine, p'robably by a process of phosphorylation. The galactose, which is the most readily absorbed of the monosaccharides, is then taken to the liver by the portal circulation, where it is normally con-verted into glycogen by the hepatic cells. Galactosaemia is a disorder of metabolism in which this conversion of galactose into glycogen is interrupted, and in consequence the blood level of the sugar rises, allowing a considerable quantity to appear in the urine. The basic cause of the disease is said to be a defective enzyme system in the liver, the exact nature of which is, as yet, unknown. Clinical features of the disease are a failure to thrive, hepatomegaly, splenomegaly, albuminuria, jaundice, cataracts, and a low blood glucose level; mental retardation is a feature of long-standing cases. A familial tendency has been noted in some of the cases reported (Goppert, 1917;