OBJECTIVE (i) To determine whether clinical features and biochemical parameters help to predict survival of methylmalonic acidemia with homocystinuria; (ii) To find the cutoff values of biochemical parameters for predicting survival of methylmalonic acidemia with homocystinuria. DESIGN A prospective cohort study. SETTING A pediatric tertiary hospital in Beijing; all patients were followed u...

We describe a gas-chromatographic procedure for determining methylmalonic acid in serum and urine. The sample is acidified and the compound is extracted from it with diethyl ether, derivatized with N,Obis(trimethylsilyl)trifluoroacetamide, and gas chromatographed. Precision and sensitivity of the method were verified by recovery studies and by comparing the resultswith those foran established p...

A rapid technique suitable for routine pathology laboratories has been used to estimate methylmalonic acid excretion in a 24-hour urine collection following a 10g. valine load. Levels above 40 mg./24 hours were found only in patients with vitamin B(12) deficiency. Patients with pernicious anaemia treated more than 24 hours before urine collection and patients with other types of anaemia had met...

BACKGROUND Urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. In the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. Gas chromatog...

The increased urinary excretion of methylmalonic acid in vitamin B12 deficiency has attracted attention and several studies have suggested that it has clinical value as a test of vitamin B12 deficiency (Cox and White, 1962; Bashir, Hinterberger, and Jones, 1966). Chromatographic methods of estimation have been used but are either time consuming or only semiquantitative over a narrow range of me...

Methylmalonic acid concentrations are increased in serum in vitamin B12 (cobalamin) deficiency. Here I demonstrate the successful use of anion-exchange extraction for improving newly developed analytical procedures and describe well-documented, reliable performance of this method for rapid determination of methylmalonic acid. The sorbent counter ion is formate, and the elution solvent is formic...

Methylmalonic aciduria is a rare disorder of organic acid metabolism with limited therapeutic options, resulting in high morbidity and mortality. Positive results from combined liver/kidney transplantation suggest, however, that metabolic sink therapy may be efficacious. Gene therapy offers a more accessible approach for the treatment of methylmalonic aciduria than organ transplantation. Accord...