Genetic influences on attention deficit hyperactivity disorder symptoms from age 2 to 3: A quantitative and molecular genetic investigation

BMC Psychiatry

Research Article

Kimberly J Saudino¹  Nicholas E Ilott²  Philip Asherson² 

[1] Psychology Department, Boston University, 64 Cummington St., Boston, MA, USA;SGDP Research Centre, Institute of Psychiatry, Kings College, London, UK;

关键词: Quantitative Trait Locus;    Attention Deficit Hyperactivity Disorder;    Club Foot;    Attention Deficit Hyperactivity Disorder Symptom;    Stratification Effect;   

DOI  :  10.1186/1471-244X-10-102

 received in 2009-11-18, accepted in 2010-12-01,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundA twin study design was used to assess the degree to which additive genetic variance influences ADHD symptom scores across two ages during infancy. A further objective in the study was to observe whether genetic association with a number of candidate markers reflects results from the quantitative genetic analysis.MethodWe have studied 312 twin pairs at two time-points, age 2 and age 3. A composite measure of ADHD symptoms from two parent-rating scales: The Child Behavior Checklist/1.5 - 5 years (CBCL) hyperactivity scale and the Revised Rutter Parent Scale for Preschool Children (RRPSPC) was used for both quantitative and molecular genetic analyses.ResultsAt ages 2 and 3 ADHD symptoms are highly heritable (h2= 0.79 and 0.78, respectively) with a high level of genetic stability across these ages. However, we also observe a significant level of genetic change from age 2 to age 3. There are modest influences of non-shared environment at each age independently (e2= 0.22 and 0.21, respectively), with these influences being largely age-specific. In addition, we find modest association signals in DAT1 and NET1 at both ages, along with suggestive specific effects of 5-HTT and DRD4 at age 3.ConclusionsADHD symptoms are heritable at ages 2 and 3. Additive genetic variance is largely shared across these ages, although there are significant new effects emerging at age 3. Results from our genetic association analysis reflect these levels of stability and change and, more generally, suggest a requirement for consideration of age-specific genotypic effects in future molecular studies.

【 授权许可】

CC BY   
© Ilott et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.