Genetic testing in children and adolescents with intellectual disabilityBass, Nicka; Skuse, DavidbCurrent Opinion in Psychiatry: November 2018 - Volume 31 - Issue 6 - p 490–495 doi: 10.1097/YCO.0000000000000456 CHILD AND ADOLESCENT PSYCHIATRY: Edited by Richa Bhatia Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review Investigation for genetic causes of intellectual disability has advanced rapidly in recent years. We review the assessment of copy number variants (CNVs) and the use of next-generation sequencing based assays to identify single nucleotide variation in intellectual disability. We discuss the diagnostic yields that can be expected with the different assays. There is high co-morbidity of intellectual disability and psychiatric disorders. We review the relationship between variants which are pathogenic for intellectual disability and the risk of child and adolescent onset psychiatric disorders. Recent findings The diagnostic yields from genome wide CNV analysis and whole exome sequence analysis are high – in the region of 15 and 40%, respectively – but vary according to exact referral criteria. Many variants pathogenic for intellectual disability, notably certain recurrent CNVs, have emerged as strong risk factors for other neurodevelopmental disorders such as autism spectrum disorders, attention deficit hyperactivity disorder, and schizophrenia. Summary It is now conceivable that etiological variants could be identified in the majority of children presenting with intellectual disability using next-generation sequencing based assays. However, challenges remain in assessment of the pathogenicity of variants, reporting of incidental findings in children and determination of prognosis, particularly in relation to psychiatric disorders. aDivision of Psychiatry, University College London bBehavioural and Brain Sciences Unit, Institute of Child Health, London, United Kingdom Correspondence to David Skuse, University College London, London, UK. Tel: 020 7905 2168; e-mail: firstname.lastname@example.org This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial License 4.0 (CCBY-NC), where it is permissible to download, share, remix, transform, and buildup the work provided it is properly cited. The work cannot be used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc/4.0 Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.