title: Aminoacidopathies and organic acidurias in Tunisia: a retrospective survey over 23 years.
abstract: BACKGROUND
  Inborn errors of metabolism are neglected in developing countries because they are not as common as infectious and nutritional disorders. In Tunisia, no information is available on the incidence and epidemiological features of these inherited metabolic diseases.
  
  
  OBJECTIVE
  To precise the profile of aminoacidopathies other than phenylketonuria and organic acidurias and to estimate their incidences in Tunisia.
  
  
  METHODS
  Between 1987 and 2009, our laboratory received 13171 requests for analysis of patients with symptoms suggestive of inborn errors of metabolism. For these cases, ion exchange chromatography of free amino acids was performed on amino acids analyser. Urinary organic acids profiles were determined by gas chromatography-mass spectrometry.
  
  
  RESULTS
  Abnormal cases were 370 (2.8%), divided into 212 cases of aminoacidopathies (57.3%) and 158 cases of organic acidurias (42.7%). The most frequent aminoacidopathies, were maple syrup disease (32.5%), tyrosinemia type I (28.8%) and nonketotic hyperglycinemia (16%). Methylmalonic aciduria (33.5%), propionic aciduria (18.4%) and 2-hyrdoxy glutaric aciduria (10.8%) were the most frequent organic acidurias. The incidences were calculated using the Hardy-Weinberg formula and were estimated at 1/13716 for maple syrup disease, 1/14804 for tyrosinemia type I, 1/16144 for methylmalonic aciduria and 1/23176 for propionic aciduria.
  
  
  CONCLUSIONS
  Aminoacidopathies and organic acidurias turned out to be highly frequent in Tunisia, mainly because of a high rate of consanguinity. We believe that they are underestimated. To improve their diagnosis, it is necessary to have available sophisticated equipment which would allow early treatment of patients.
authors.affiliation: Laboratory of Biochemistry, Rabta Hospital, Tunis, Tunisia.
authors.forename: Sameh
authors.initials: S
authors.lastname: Hadj-Taieb
authors.forename: Fehmi
authors.initials: F
authors.lastname: Nasrallah
authors.forename: Mohamed B
authors.initials: MB
authors.lastname: Hammami
authors.forename: Monia
authors.initials: M
authors.lastname: Elasmi
authors.forename: Haifa
authors.initials: H
authors.lastname: Sanhaji
authors.forename: Feki
authors.initials: F
authors.lastname: Moncef
authors.forename: Naziha
authors.initials: N
authors.lastname: Kaabachi
mesh_terms: D000293:Adolescent; D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis* / Q000453:epidemiology*; D020157:Amino Acid Transport Disorders, Inborn / Q000175:diagnosis / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods; D012189:Retrospective Studies; D013997:Time Factors; D014416:Tunisia / Q000453:epidemiology; D055815:Young Adult