title: Multiplex ligation-dependent probe amplification to subtelomeric rearrangements in idiopathic intellectual disability in Colombia.
abstract: BACKGROUND
  A cause cannot be determined in 30% to 50% of patients with intellectual disability. Determining the etiology of intellectual disability is important and useful for pediatric neurologists, geneticists, pediatricians, and patients' families because it allows assessment of recurrence risk, appropriate genetic counseling, and focus on treatment options and prognosis. This study aims to determine the prevalence, origin, and characterization of subtelomeric rearrangements through the Multiplex Ligation-Dependent Probe Amplification method in pediatric patients with idiopathic intellectual disability.
  
  
  METHODS
  A cross-sectional descriptive study was undertaken with patients seen in consultation at the neuropediatrics or genetic service of the Central Military Hospital, the Mercy' Hospital, or the Genetics Institute National University of Colombia. Patients were diagnosed with idiopathic intellectual disability between December 2010 and September 2011 and underwent a complete medical history, physical examination, and assessment to rule out other etiologies of intellectual disability. Then we applied the genetic test of Multiplex Ligation-Dependent Probe Amplification to each patient's sample of peripheral blood to determine subtelomeric rearrangements.
  
  
  RESULTS
  We studied a group of 119 patients with idiopathic intellectual disability; Multiplex Ligation-Dependent Probe Amplification showed subtelomeric rearrangements in five. In the group with subtelomeric rearrangements, the most frequent results were de novo rearrangements (80%), deletion type (60%), moderate and severe intellectual disability (80%), minor phenotypic abnormalities (80%), and family history of neurological disorders (80%). No dependence relationship was observed between subtelomeric rearrangements and family history of neurological disorders, family history of intellectual disability, severity of intellectual disability, phenotypic abnormalities, and consanguinity.
  
  
  CONCLUSIONS
  This study determined a prevalence of subtelomeric rearrangements of 4.2% in a group of Colombian pediatric patients with idiopathic intellectual disability using the genetic test Multiplex Ligation-Dependent Probe Amplification.
authors.affiliation: Department of Pediatric Neurology, Central Military Hospital, Bogota, Colombia. Electronic address: amina8.ada@gmail.com.
authors.forename: Adalbeis
authors.initials: A
authors.lastname: Medina
authors.affiliation: Genetics Institute National University of Colombia, Bogota, Colombia.
authors.forename: Lorena
authors.initials: L
authors.lastname: Piñeros
authors.affiliation: Genetics Institute National University of Colombia, Bogota, Colombia.
authors.forename: Clara
authors.initials: C
authors.lastname: Arteaga
authors.affiliation: Genetics Institute National University of Colombia, Bogota, Colombia.
authors.forename: Harvy
authors.initials: H
authors.lastname: Velasco
authors.affiliation: Department of Pediatric Neurology, National University of Colombia, Bogota, Colombia.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Izquierdo
authors.affiliation: Genetics Institute National University of Colombia, Bogota, Colombia.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Giraldo
authors.affiliation: Department of Pediatric Neurology, Central Military Hospital, Bogota, Colombia.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Espinosa
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003105:Colombia; D003430:Cross-Sectional Studies; D005190:Family; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology* / Q000235:genetics*; D008297:Male; D009154:Mutation; D010641:Phenotype; D012720:Severity of Illness Index; D016615:Telomere
keywords: MLPA; intellectual disability; mental retardation; subtelomeric rearrangements