This study seeks to determine if the administration of oral uridine to patients with classical galactosemia, at a dosage of 150 mg/kg/day, as an adjunct to treatment with conventional lactose restriction, will improve the long term outcome and biochemical alterations seen in this disorder. Two groups of patients will be treated between 3 and 13 years of age. Forty patients will be matched by age and sex and one subject from each pair will be randomly assigned to the treatment or placebo group. In addition, 10 children under one year of age will be treated with oral uridine as soon after birth as possible. To assess whether uridine treatment improves neuropsychologic, neurologic,communicative and ovarian function, specific tests able to delineate subtle change in these areas will be serially performed over the 5 year study period. Erythrocyte uridine diphosphate galactose (UDPGal) will be followed to insure that uridine therapy improves UDPGal production. Erythrocyte galactose-1-phosphate (Gal 1-P) will be measured and it is anticipated that uridine will not increase Gal-1-P levels. Biochemical studies will be performed to determine the activities of UDPGal and uridine diphosphate glucose pyrophosphorylase(s) and to differentiate through which intermediates UDPGal is increased in response to uridine intervention. Specific galactolipid and galactoprotein compounds will be analyzed to determine how UDPGal deficiency and uridine treatment affect the synthesis of complex galactose containing macromolecules. Specific galactose-1-phosphate uridyltransferase gene mutations will be determined and correlated with the clinical and biochemical response to uridine treatment.
