Galactokinase Deficiency as a Cause of Cataracts

Galactokinase and galactose-1-phosphate uridyl transferase assays were carried out on blood samples from 210 persons in whom cataracts developed before the age of 40. In two patients, both of whom were first noted to have cataracts during the first year of life, total galactokinase deficiency was found. Among the other 92 patients whose cataracts had developed during the first year of life there was a statistically significant lowering of galactokinase activity. No cases of total galactokinase deficiency or concentrations of galactokinase reduced to a statistically significant degree were found in the patients whose cataracts developed later in life. One subject was found to have a total lack, and one approximately 1/6 normal galactose-1-phosphate uridyl transferase activity. Severe defects of galactose metabolism occur often enough among patients with juvenile cataracts of unknown cause that assays for galactokinase and galactose-1-phosphate uridyl transferase should be carried out in such cases. (N Engl J Med 288:1203–1206, 1973)