Combined methylmalonic acidemia (MMA) and homocysteinemia are a group of autosomal recessive disorders caused by inborn errors of cobalamin metabolism, including CblC, D, F, and J, with cblC being the most common subtype. The clinical manifestations of combined MMA and homocysteinemia vary, but typically include neurologic, developmental and hematologic abnormalities.We report 4 children with c...

We developed a radioimmunoassay to quantitate material crossreacting immunochemically with human methylmalonyl-CoA mutase (methylmalonyl-CoA CoA-carbonylmutase, EC 5.4.99.2), and have applied this assay to extracts of fibroblasts from controls and from 32 patients with methylmalonic acidemia due to inherited deficiencies in mutase activity. Four control lines had an average of 237 ng of crossre...

Many inborn errors of metabolism are characterized by an increase in the concentrations of various carboxylic acids in blood and urine. For example, the metabolic disorders propionic acidemia [ 11, methylmalonic aciduria [ 2,3], maple syrup urine disease [4], isovaleric acidemia [ 41 and glutaric aciduria type II [ 5,6] show increased amounts of volatile carboxylic acids in blood or urine. Proc...

Neurologic regression in a previously healthy child may be caused by metabolic or neurodegenerative disorders, many of which have no definitive treatment. We report a case of a previously healthy 8-year-old boy who presented with a month-long history of waxing and waning encephalopathy and acute regression, followed by seizures. Evaluation for a metabolic disorder revealed methylmalonic acidemi...

immidiate managementinfants and children with acute metabolic crisis require immediate treatment to prevent further acute deterioration and long-term sequelae.early and appropriate treatment before confirmation of the diagnosis is life-saving.eliminate intake of the precursors of possibly toxic metabolites.this applies most often to suspected inborn errors of amino acid or organic acid metaboli...

We investigated the compartmentation of the catabolism of dodecanedioate (DODA), azelate, and glutarate in perfused rat livers, using a combination of metabolomics and mass isotopomer analyses. Livers were perfused with recirculating or nonrecirculating buffer containing one fully (13)C-labeled dicarboxylate. Information on the peroxisomal versus mitochondrial catabolism was gathered from the l...

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...