Contents

Disclaimer

Oxford University Press makes no representation, express or implied, that the drug dosages in this book are correct. Readers must therefore always check the product information and clinical procedures with the most up to date published product information and data sheets provided by the manufacturers and the most recent codes of conduct and safety regulations. The authors and the publishers do not accept responsibility or legal liability for any errors in the text or for the misuse or misapplication of material in this work. Except where otherwise stated, drug dosages and recommendations are for the non-pregnant adult who is not breastfeeding.

Show Summary Details
Page of

Syndromes causing intellectual disability 

Syndromes causing intellectual disability
Chapter:
Syndromes causing intellectual disability
Author(s):

David M. Clarke

and Shoumitro Deb

DOI:
10.1093/med/9780199696758.003.0244
Page of

PRINTED FROM OXFORD MEDICINE ONLINE (www.oxfordmedicine.com). © Oxford University Press, 2021. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 27 January 2021

Psychiatrists working with people who have intellectual disability (mental retardation) need expertise in the diagnosis and treatment of associated neuropsychiatric disorders. This entails knowledge of the causes of intellectual disability, and especially knowledge about those syndromal (often genetic) causes that are associated with neuropsychiatric manifestations. Such manifestations include vulnerability to behavioural and emotional disorders, epilepsy, and particular patterns of cognitive strength and weakness. This chapter provides an introduction to some such disorders and a discussion of the concept of behavioural phenotypes. For a detailed account of conditions causing intellectual disability texts such as Jones should be consulted. The concept of behavioural phenotypes is discussed in detail in O’Brien. The genetic aetiologies of intellectual disability include chromosomal abnormalities (trisomy, deletion, translocation, etc), single-gene defects, and the effect of interactions between several genes. The last is thought to account for a substantial proportion of people with mild intellectual disability by setting a ceiling on possible cognitive attainment (life experiences, nutrition, education, and other factors then determining the extent to which potential is fulfilled or thwarted). This chapter discusses the concepts of syndromes and behavioural phenotypes, then describes the clinical features of a number of syndromes that cause intellectual disability. Down syndrome, fragile-X syndrome, sex chromosome anomalies, and foetalalcohol syndrome are described in some detail. This is followed by a briefer alphabetical list of less common conditions.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.