Clinical significance of plasma galactose and erythrocyte galactose-1-phosphate measurements in transferase-deficient galactosemia and in individuals with below-normal transferase activity.

We correlated the clinical symptoms of transferase-deficient galactosemia with the plasma galactose and erythrocyte galactose-1-phosphate concentrations in six galactosemic patients during dietary treatment, in a child before treatment, and in 12 individuals with below-normal erythrocyte hexose-1-phosphate uridylyltransferase activity. All the treated patients were asymptomatic. Normal galactose and either normal or above-normal galactose-1-phosphate concentrations were found. Three of these patients were clinically normal as newborns while ingesting galactose-containing foods and may resemble the asymptomatic Negro galactosemic. The clinical symptoms of galactosemia were observed in the untreated patient, who showed markedly above-normal concentrations of galactose and galactose-1-phosphate, protein and reducing substances in the urine, above-normal bilirubin and alkaline phosphatase in the plasma, with normal values for glucose, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase. Clinical improvement in this patient paralleled the decline in erythrocyte galactose-1-phosphate. The individuals with below-normal hexose-1-phosphate uridylyltransferase activity (range 7--17 U/g of hemoglobin) had normal galactose and galactose-1-phosphate concentrations and were asymptomatic.