Galactokinase Deficiency in Twins: Clinical and Biochemical Studies.

Identical twin girls with galactokinase deficiency are described. The diagnosis was made at 4 months of age when a random urinalysis in one twin showed a non-glucose reducing substance subsequently identified as galactose. Clinical findings were limited to bilateral perinuclear cataracts in both infants. There was no jaundice or hepatomegaly. While receiving an evaporated milk formula, the urines contained large amounts of galactose and galactitol. Erythrocyte galactokinase activity was absent in both patients, and 50% of normal activity was found in both parents. A "lactose-free" formula was instituted at 4 1/2 months of age. Growth and development has been normal over 24 months of treatment. The cataracts, however, showed no significant change. Galactose and galactitol excretion was markedly decreased, but not completely eliminated. The turnover of endogenous galactose-containing compounds may be responsible for the residual galactose and galactitol excretion. [ABSTRACT FROM AUTHOR]