Outcome of early and long-term management of classical maple syrup urine disease

Abstract

The outcome of 8,400 treatment days in the lives of 4 patients with classical maple syrup urine disease (MSUD) (present ages: 1 3/12, 5 7/12, 7 1/12, and 8 11/12 years) are described. Each diagnosis was made by clinical signs rather than by newborn screening. Acute-phase treatment beginning on the 11th day of life comprised peritoneal dialysis, intravenous lipid, and early intestinal alimentation. Mean age at discharge from hospital was 29 days. There were 16 readmissions to the hospital for the group (89 days, 1.05% treatment days) without any serious neurologic symptoms. The mean level of plasma leucine for the group (for levels below 1 mM) during treatment was 0.42 mM (normal for age range, 0.077 ± 0.021 mM [mean ± SD]). Plasma leucine exceeded 1 mM during 1.02% of treatment days (representing 8.6% of 1,042 measurements. Mean levels of plasma valine and isoleucine were 60% and 70% of the plasma leucine value for the group. Tolerance for dietary leucine did not exceed 620 mg/day in any patient. Somatic growth was normal and the mean current IQ/development quotient (DQ) score is 101 (range 89 to 117); the 3 oldest patients attend regular schools. A characteristic EEG pattern resembling the teeth of a comb was observed in 3 patients during the acute phase in the newborn period but not during long-term treatment. These results were obtained in an ambulatory program with home visiting.