title: Unexplained developmental delay/learning disability: guidelines for best practice protocol for first line assessment and genetic/metabolic/radiological investigations.
abstract: BACKGROUND
  Investigation of patients, particularly children, with unexplained global developmental delay (GDD)/learning disability (LD) has been challenging due to a lack of clear guidance from specialised centres. Limited knowledge of rare diseases and a poor understanding of the purpose or limitations of appropriate investigations have been some of the principal reasons for this difficulty.
  
  
  OBJECTIVE
  A guideline development group was formed to recommend on appropriate, first line metabolic, genetic and radiological investigations for children and adults with unexplained GDD/ID.
  A comprehensive literature search was conducted, evaluated and reviewed by the guideline committee and a best practice protocol for first line assessment and genetic, metabolic and radiological investigations was decided upon after considering diagnostic yield, practicality, treatability and costs.
  
  
  CONCLUSIONS
  It is hoped that these recommendations will become national guidelines for the first line metabolic, genetic and radiological investigation of patients presenting with unexplained GDD/ID.
authors.affiliation: Department of Clinical Genetics, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland. obyrnej@tcd.ie.
authors.forename: J J
authors.initials: JJ
authors.lastname: O'Byrne
authors.affiliation: Department of Clinical Genetics, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland.
authors.forename: S A
authors.initials: SA
authors.lastname: Lynch
authors.affiliation: National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin 1, Ireland.
authors.forename: E P
authors.initials: EP
authors.lastname: Treacy
authors.affiliation: Department of Neurology, Temple Street Children's University Hospital, Dublin 1, Ireland.
authors.forename: M D
authors.initials: MD
authors.lastname: King
authors.affiliation: Department of Clinical Genetics, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland.
authors.forename: D R
authors.initials: DR
authors.lastname: Betts
authors.affiliation: Department of Biochemistry, Temple Street Children's University Hospital, Dublin 1, Ireland.
authors.forename: P D
authors.initials: PD
authors.lastname: Mayne
authors.affiliation: Department of Paediatrics, Midland Regional Hospital, Mullingar, Co. Westmeath, Ireland.
authors.forename: F
authors.initials: F
authors.lastname: Sharif
mesh_terms: D000328:Adult; D002648:Child; D002658:Developmental Disabilities / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007859:Learning Disabilities / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D008661:Metabolism, Inborn Errors / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D035583:Rare Diseases
keywords: First line investigations; Global developmental delay; Guidelines; Learning disability