Recent advances in behavioural phenotypes as they affect adults
| DOI | https://doi.org/10.1108/20441281111165553 |
| Date | 15 July 2011 |
| Published date | 15 July 2011 |
| Pages | 5-14 |
| Author | Gregory O'Brien,Ruth Bevan |
| Subject Matter | Health & social care,Learning & intellectual disabilities |
Recent advances in behavioural
phenotypes as they affect adults
Gregory O’Brien and Ruth Bevan
Abstract
Purpose – This paper seeks to discuss the complexity of the relationship between genotype and
phenotype and highlight the importance of a greater understanding of behavioural phenotypes in
genetic syndromes. The aim is to explore the developmental trajectory of the behavioural phenotypes as
individuals emerge from childhood into adulthood and beyond.
Design/methodology/approach – Information was gathered from a search of the relevant literature
over the past 20 years using Medline and PsycINFO databases in May 2010 as well as information
published in textbooks on this matter.
Findings – The outcomes were considered under five areas of functioning: cognition, communication,
behaviour,social functioning and propensity to psychiatric illnesses. The research thus far suggests that
outcomes in behavioural phenotypes in adults are extremely variable.Individual predictions are difficult
to make. However, some trends do emerge.
Originality/value – Findings of particular interest are the rates of attention deficit hyperactivity disorder
and autism spectrum conditions and how these change over the developmental trajectory. The paper
highlights the need for further research in this area and discusses the need to view behavioural
phenotypes as a continuum across the lifespan.
Keywords Adult outcomes, Behavioural phenotypes, Developmental trajectory, Genetic syndromes,
Intellectual disability, Learning disabilities, Chromosomes
Paper type Research paper
Introduction
‘‘But will (s)he grow out of it?’’ This question, however, articulated, is always foremost among
the concerns of parents and carers of children newly diagnosed with genetic conditions
resulting in intellectual disability (O’Brien, 2001). The underlying question is – how much can
genotype determine adult outcome, whether in terms of intelligence, behaviour,
development, psychiatric disorders, general health or eventual adult functioning in society?
Clearly,there are a multitude of factors, in addition to genetics,which influence outcomes. This
is, particularly relevant in the population of people with intellectual disability where factors
include substandard health care, lifestyles and education (O’Brien, 2001). Therefore, the
relationship between genotype and phenotype is not a simple one, especially when we
consider the developmental trajectory from childhood to adulthood.
The underpinninggenes and presence of a genetic condition set limits on the developmental
trajectory, as seen in the overall associations of intelligent quotient (IQ) ranges in individual
syndromes (Table I). In addition, the individual’s temperament and other innate traits impact
upon their development through theirinteractions with, and reactionsfrom, others. Be it motor
restlessness,aberrant social behaviour or propensity towards dysphoric mood, all affecthow
someone ‘‘fits into’’ society. The term ‘‘environtype’’ is sometimes used to describe the
mechanismsby which other people’s reactionsto geneticallydetermined traits impactupon the
expressionof the latter and, ultimately,upon individual development(O’Brien and Yule, 1995).
DOI 10.1108/20441281111165553 VOL. 5 NO. 4 2011, pp. 5-14, QEmerald Group Publishing Limited, ISSN 2044-1282
j
ADVANCES IN MENTALHEALTH AND INTELLECTUAL DISABILITIES
j
PAGE 5
Gregory O’Brien is Emeritus
Professor of Developmental
Psychiatry at Northumbria
University, Newcastle upon
Tyne, UK.
Ruth Bevan is a Specialist
Trainee in Learning
Disability Psychiatry
Northumberland, Tyne and
Wear NHS Foundation
Trust, Morpeth, UK.
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