Certain amino acids and other compounds are metabolized via: Propionyl-CoA carboxylase in equilibrium D-methylmalonyl-CoA racemase in equilibrium L-methylmalonyl-CoA (adenosylcobalamin) mutase in equilibrium succinyl-CoA in equilibrium tricarboxylic acid cycle. In cobalamin deficiency and in genetic disorders involving adenosylcobalamin or the mutase, large amounts of methylmalonic acid are exc...

1. Twenty.one patients with liver diseases were studied for their urinary mehylmalonic acid excretion after a valine load by means of an improved thin layer chromatography. 2. Methylmalonic acid positive cases were found in four out of the ten patients with cirrhosis of the liver, all four with cirrhosis and diabetes mellitus, and none with acute hepatitis of icteric phase. No apparent correlat...

I . A semi-synthetic vitamin B,,-deficient diet, based on soya flour, is described. When supplemented with cydnocobalamin the diet appeared to be adequate for growth and reproduction in the rat. 2. Compared with their litter-mates on the supplemented diet, rats fed on the deficient diet from weaning showed reduced levels of vitamin Biz activity in the plasma and tissues, but their growth rates ...

We have identified 12 patients with autosomal recessive mitochondrial encephalomyopathy with elevated methylmalonic acid. The disorder has a high incidence of 1 in 1700 in the Faroe Islands due to a founder effect, and a carrier frequency of 1 in 33. The symptoms comprise hypotonia, muscle atrophy, hyperkinesia, severe hearing impairment and postnatal growth retardation. Neuroimaging showed dem...

To clarify the relationship between intracellular concentrations of methylmalonic acid and metabolic and growth inhibition in vitamin B12-deficient rats, hepatic methylmalonic acid levels were assayed and inhibition of glucose and glutamic acid metabolism by methylmalonic acid was studied in isolated hepatocytes. Vitamin B12-deficient rats (14 weeks old) excreted more urinary methylmalonic acid...

An automated method for estimation of methylmalonic acid in urine is described that compares well with results obtained by a manual method. The temperature at which color is developed can be set anywhere between ambient and 90°C without loss of linearity over a certain range of concentrations. The higher temperatures have greater sensitivity but a smaller linear range than do lower incubation-t...

Materials and Methods: Fifty women having migraine without aura were matched with healthy controls (n=6) with the same age distribution. Fasting serum vitamin B12, folate, plasma total homocysteine (tHcy) and first morning urine methylmalonic acid (MMA) levels were determined in patient and control groups. Statistical differences in laboratory parameters between patient and control groups were ...

clinical differential diagnosisthe organic acidemias are important in the differential diagnosis of metabolic and neurologic derangement in the neonate and of new-onset neurologic signs in the older child. a-organic aciduriaseveral disorders, not classified as primary disorders of organic acid metabolism, have a characteristic urinary organic acid profile that suggests the appropriate diagnosis...

OBJECTIVE To examine the relationship between the two diagnostic tests, plasma methylmalonic acid and plasma cobalamins, and their association with plasma creatinine, age and sex. DESIGN Cross-sectional study of simultaneous laboratory measurements. SETTING County of Aarhus, Denmark. SUBJECTS Records on 1689 patients who had their first plasma methylmalonic acid measurement during 1995 an...