Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Genetic influences on attention deficit hyperactivity disorder symptoms from age 2 to 3: A quantitative and molecular genetic investigation | Ilott et al. BMC Psychiatry 2010 10 102 http 1471-244X 10 102 BMC Psychiatry RESEARCH ARTICLE Open Access Genetic influences on attention deficit hyperactivity disorder symptoms from age 2 to 3 A quantitative and molecular genetic investigation Nicholas E Ilott1 Kimberly J Saudino2 Philip Asherson1 Abstract Background A 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. Method We 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 - 5 years CBCL hyperactivity scale and the Revised Rutter Parent Scale for Preschool Children RRPSPC was used for both quantitative and molecular genetic analyses. Results At ages 2 and 3 ADHD symptoms are highly heritable h2 and 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 and 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. Conclusions ADHD 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. Background Attention Deficit Hyperactivity Disorder ADHD is a common .
