title: [Characterization of inborn errors of intermediary metabolism in mexican patients].
abstract: BACKGROUND
  Inborn errors of intermediary metabolism (IEiM) are a group of heterogeneous genetic diseases that are diagnostically challenging and cause significant morbidity and mortality. The aim of this study is to perform a descriptive analysis of the number, type, and clinical features, in a series of cases with IEiM identified through selective diagnosis in a highly specialized pediatric hospital.
  
  
  METHODS
  A retrospective study was performed from January of 2000 to December of 2012 by analyzing the files of 204 patients with an IEiM, by selective screening, before and after the implementation of tandem mass spectrometry (MS/MS).
  
  
  RESULTS
  A total of 25 different types of IEiM were found in the 204 files; 102 organic acidurias, 100 aminoacidopathies, and 2 fatty acid oxidation disorders. The introduction of MS/MS increased the number of cases detected by 50%. Patients were referred from 13 different specialists, with pediatricians being the most active. The average interval between onset of symptoms and diagnosis was 18 months.
  
  
  CONCLUSIONS
  Among the sick Mexican children studied, a wide variety of IEiM was found, propionate defects and maple syrup urine disease being noteworthy. The diagnosis of metabolic disease was delayed in the population studied. These results present evidence to perhaps incorporate IEiM into an expanded newborn screening, or else to perform selective diagnosis in all hospitalized children with suggestive clinical data.
authors.affiliation: Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México.
authors.forename: I
authors.initials: I
authors.lastname: Ibarra-González
authors.affiliation: Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México.
authors.forename: C
authors.initials: C
authors.lastname: Fernández-Lainez
authors.affiliation: Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México.
authors.forename: L
authors.initials: L
authors.lastname: Belmont-Martínez
authors.affiliation: Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México.
authors.forename: S
authors.initials: S
authors.lastname: Guillén-López
authors.affiliation: Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México.
authors.forename: S
authors.initials: S
authors.lastname: Monroy-Santoyo
authors.affiliation: Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, México. Electronic address: dravelaamieva@yahoo.com.
authors.forename: M
authors.initials: M
authors.lastname: Vela-Amieva
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000453:epidemiology*; D008800:Mexico; D012189:Retrospective Studies
keywords: Acidurias orgánicas; Aminoacidopathies; Aminoacidopatías; Defectos de oxidación de ácidos grasos; Diagnóstico selectivo; Errores innatos del metabolismo; Fatty acid oxidation disorders; High-risk screening; Inborn errors of metabolism; Organic acid disorders; Selective diagnosis; Tamiz selectivo