Selective screening for organic acidemias by urine organic acid GC-MS analysis in Brazil: fifteen-year experience.
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.
Wajner
Moacir
M
Serviço de Genética Médica, Hospital de Clínicas, Porto Alegre, RS, Brazil. mwajner@ufrgs.br
Coelho
Daniella de Moura
Dde M
Ingrassia
Rafaela
R
de Oliveira
Anderson Büker
AB
Busanello
Estela Natacha Brandt
EN
Raymond
Kimiyo
K
Flores Pires
Ricardo
R
de Souza
Carolina Fischinger Moura
CF
Giugliani
Roberto
R
Vargas
Carmen Regla
CR
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
D002264:Carboxylic Acids