Results We diagnosed 148 cases of IEM by urine GC-MS analysis, including 97 cases of organic acid disorders, 41 cases of amion acid disorders and 10 cases of fatty acid oxidative disorders. Methylmalonic aciduria (MMA) was most common (48 cases), followed by urea cycle disorder (21 cases), phenylketonuria (20 cases), propionic aciduria (11 cases), multiple carboxylase deficiency (8 cases), glut...

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...

Methylmalonic acid (MMA) is a biomarker for vitamin B12 deficiency. This application note describes a fast, simple, and sensitive method to detect MMA in plasma that uses a zwitterionic hydrophilic interaction chromatography (ZIC®-HILIC) column with LC-MS or LC-MS/MS. Introduction Methylmalonic acid (MMA) levels in serum, plasma and urine are used to monitor cobalamin (vitamin B12) deficiency1 ...

BACKGROUND The present study was undertaken to investigate the clinical characteristics of hemolytic uremic syndrome (HUS) secondary to cobalamin C disorder (cbl-C disorder). METHODS We reviewed retrospectively the medical records of 3 children with HUS secondary to cbl-C disorder who had been treated between April 1, 2009 and October 31, 2013. RESULTS The 3 patients with HUS secondary to c...

how to cite this article: karimzadeh p, jafari n, jabbehdari s, taghdiri mm, nemati h, saket s, alaee mr, ghofrani m, tonakebni sh. methylmalonic acidemia: diagnosis and neuroimaging findings of this neurometabolic disorder (an iranian pediatric case series). iran j child neurol. 2013 summer; 7(3): 63-66.   objective methylmalonic acidemia is one of the inborn errors of metabolism resulting in ...

BACKGROUND Methylmalonic acid (MMA) is a dicarboxylic acid whose concentration can be increased in blood and urine in patients with an inborn error of metabolism or vitamin B(12) deficiency. We developed a method for the selective analysis of dicarboxylic acids that exploits the high specificity of tandem mass spectrometry (MS/MS) and the substantial difference in fragmentation patterns of the ...

Chronic arsenic (As) exposure currently affects more than 100 million people worldwide. Methylation of ingested inorganic arsenic (InAs) to methylarsonic(MMA) and dimethylarsinic acids (DMA) relies on folate-dependent one carbon metabolism. In a recent, randomized, controlled trial, we analyzed total As and As metabolites in urine and showed that folic acid supplementation resulted in an increa...

Two human subjects were given separate oral doses of sodium [2H6]isobutyrate and [methyl-2H3]thymine and the labelling patterns of urinary metabolites were determined. Ingestion of deuterated isobutyrate resulted in the excretion of 2H5-labelled S-3-hydroxyisobutyric acid, formed on the direct catabolic pathway, and of S- and R-[2H4]-3-hydroxyisobutyric acids, formed by the reduction of S- and ...

Positive-ion thermospray liquid chromatography-mass spectrometry (TSP-LC-MS) is used to detect organic acids via the direct injection of untreated urine from newborns and infants. Two methods are reported for the separation of organic acids. The separation of urinary organic acids is effected in either an acidic, pH 2.5 sulfuric acid, or a non-acidic, 0.05 M ammonium acetate, pH 6.8, mobile pha...