inherited disease, 7th ed. New York: McGraw-Hill, 1995:791–801. 5. Tanaka K, Orr JC, Isselbacher KJ. The identification of -hydroxyisovaleric acid in the urine of a patient with isovaleric acidemia. Biochem Biophys Acta 1968;152:638–41. 6. Tanaka K, Ikeda Y, Matsubara Y, Hyman D. Molecular basis of isovaleric acidemia in the study of the acyl-CoA dehydrogenase family. Adv Neurol 1988;48:107–31....

It is well established that accumulation of methylmalonic acid may provide an early clue to the existence of tissue cobalamin (vitamin B12) deficiency. To verify whether methylmalonic acid accumulates in adult heterozygotes for inherited methylmalonic-acidaemia and thereby gives "false" positive test results for cobalamin deficiency, we measured the concentration of methylmalonic acid in serum ...

Most organic acidemias become clinically apparent during neonatal period or early infancy. Infants typically have severe metabolic acidosis with increased anion gap, ketosis and hyperammonemia. Extremely high ammonia levels exceeding 1000 μmol/L is a discriminative feature for urea cycle defect while levels exceeding 200-300 μmol/L are rarely encountered in other reasons of hyperammonemia. Leth...

Methylmalonic aciduria and homocystinuria, cblC type, is the most common inborn error of vitamin B(12) (cobalamin) metabolism. The recent cloning of the disease gene, MMACHC, has permitted genotype-phenotype correlation. In a 1-year-old girl, compound heterozygous c.271dupA and c.616C>T mutations in MMACHC were identified as causing an early onset methylmalonic aciduria and homocystinuria, cblC...

All the metabolically important C1 through C5 fatty acids and lactic, pyruvic and fl-hydroxybutyric acids can be gas chromatographed surprisingly well on the common 2-meter 3% methylphenylsilicone (e.g., “OV-17”) column when a late-eluting silylating reagent such as trimethylsilylimidazole is used. In these circumstances, the trimethylsilyl esters elute in an interval that is free of the reagen...