title: Abnormal organic acidurias in mentally retarded patients.
abstract: Urine specimens from 1778 mentally retarded patients and 420 age and sex matched non-retarded controls selected from a general practice have been analysed for non-amino organic acids by a quantitative extraction and gas chromatographic method. The compounds were identified by combined gas chromatography and mass spectrometry. Approximately 5% of the patients had an abnormal organic aciduria. The frequency of abnormalities was slightly higher (about 7%) in a group of 248 severely subnormal children, but not in cases with a family history of mental retardation, retarded sibs, or whose parents were consanguineous. The most frequently observed abnormalities were phenylalanine metabolites in cases of phenylketonuria (about 1%), increased excretion of benzoic acid (about 1%), and increased excretion of 2-oxoglutaric acid with or without raised urinary citric-acid levels (about 1%). The biochemical and clinical significance of these findings is being further investigated.
mesh_terms: D000138:Acidosis / Q000209:etiology; D000143:Acids / Q000652:urine*; D000328:Adult; D001565:Benzoates / Q000652:urine; D002648:Child; D002849:Chromatography, Gas; D002951:Citrates / Q000652:urine; D005260:Female; D006016:Glycolates / Q000652:urine; D006719:Homovanillic Acid / Q000652:urine; D006801:Humans; D006885:Hydroxybutyrates / Q000652:urine; D008607:Intellectual Disability / Q000175:diagnosis / Q000209:etiology / Q000235:genetics / Q000652:urine*; D007656:Ketoglutaric Acids / Q000652:urine; D007773:Lactates / Q000652:urine; D008297:Male; D008314:Malonates / Q000652:urine; D013058:Mass Spectrometry; D008661:Metabolism, Inborn Errors / Q000652:urine*; D010648:Phenylacetates / Q000652:urine; D010649:Phenylalanine / Q000652:urine; D010661:Phenylketonurias / Q000652:urine; D013048:Specimen Handling; D013386:Succinates / Q000652:urine
chemical_list: D000143:Acids; D001565:Benzoates; D002951:Citrates; D006016:Glycolates; D006885:Hydroxybutyrates; D007656:Ketoglutaric Acids; D007773:Lactates; D008314:Malonates; D010648:Phenylacetates; D013386:Succinates; D010649:Phenylalanine; D006719:Homovanillic Acid