title: Selective screening for organic acidemias by urine organic acid GC-MS analysis in Brazil: fifteen-year experience.
abstract: BACKGROUND
  The gas chromatography/mass spectrometry (GC/MS) method for organic acid analysis was established in developed countries since 1980s, but due to the small number of experienced clinical biochemists in this field and also the short availability of mass spectrometers scarce reports exist on the prevalence of organic acidemias (OAs) in developing countries like Brazil.
  
  
  METHODS
  During January 1994 to July 2008, we analyzed organic acids by GC/MS in urine specimens obtained from Brazilian children with clinical suspicion of metabolic diseases.
  
  
  RESULTS
  Two hundred and thirty four cases of disorders of organic acid metabolism, including 218 OAs (3.17%), were diagnosed among 6866 patients investigated. The most frequent disorders were primary lactic acidemia (57), methylmalonic acidemia (34), glutaric acidemia type I (33), propionic acidemia (18), 3-hydroxy-3-methylglutaric aciduria (17), L-2-hydroxyglutaric aciduria (9) and multiple carboxylase deficiency (9). Fourteen cases of mitochondrial fatty acid oxidation disorders, as well as 12 aminoacidopathies and 4 cases of vitamin B12 deficiency were also detected. Prompt treatment following diagnosis led to a better outcome in a considerable number of patients.
  
  
  CONCLUSIONS
  Detection of OAs in loco in developing countries is important despite the implied extra costs, since it allows rapid therapy in many cases with a significant reduction of morbidity and mortality and makes the physicians more aware of these pathologies.
authors.affiliation: Serviço de Genética Médica, Hospital de Clínicas, Porto Alegre, RS, Brazil. mwajner@ufrgs.br
authors.forename: Moacir
authors.initials: M
authors.lastname: Wajner
authors.forename: Daniella de Moura
authors.initials: Dde M
authors.lastname: Coelho
authors.forename: Rafaela
authors.initials: R
authors.lastname: Ingrassia
authors.forename: Anderson Büker
authors.initials: AB
authors.lastname: de Oliveira
authors.forename: Estela Natacha Brandt
authors.initials: EN
authors.lastname: Busanello
authors.forename: Kimiyo
authors.initials: K
authors.lastname: Raymond
authors.forename: Ricardo
authors.initials: R
authors.lastname: Flores Pires
authors.forename: Carolina Fischinger Moura
authors.initials: CF
authors.lastname: de Souza
authors.forename: Roberto
authors.initials: R
authors.lastname: Giugliani
authors.forename: Carmen Regla
authors.initials: CR
authors.lastname: Vargas
mesh_terms: D001364:Awareness; D001938:Brazil / Q000453:epidemiology; D002264:Carboxylic Acids / Q000652:urine*; D002648:Child; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods*; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology / Q000652:urine*; D015995:Prevalence; D012306:Risk; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D002264:Carboxylic Acids