title: No evidence for the association of DRD4 with ADHD in a Taiwanese population within-family study.
abstract: BACKGROUND
  Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent and highly heritable childhood disorder. The dopamine D4 receptor (DRD4) gene has shown a genetic association with ADHD in Caucasian populations with meta-analysis indicating a small but significant effect across datasets. It remains uncertain whether this association can be generalised to non-Caucasian ethnic groups. Here we investigate two markers within the DRD4 gene in a Taiwanese population, the exon 3 variable number tandem repeat (VNTR) and a 5' 120 base-pair duplication.
  
  
  METHODS
  Within-family transmission disequilibrium tests of association of the 5' 120 base-pair duplication, and exon 3 VNTR in a Taiwanese population.
  
  
  RESULTS
  No evidence of association of ADHD with either polymorphism in this population was observed.
  
  
  CONCLUSIONS
  The DRD4 gene markers investigated were not found to be associated with ADHD in this Taiwanese sample. Further work in Taiwanese and other Asian populations will therefore be required to establish whether the reports of association of DRD4 genetic variants in Caucasian samples can be generalised to Asian populations.
authors.affiliation: MRC Social Genetic Developmental Psychiatry Centre, Institute of Psychiatry, London, UK. k.brookes@iop.kcl.ac.u
authors.forename: Keeley-Joanne
authors.initials: KJ
authors.lastname: Brookes
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
authors.forename: Chih-Ken
authors.initials: CK
authors.lastname: Chen
authors.forename: Yu-Shu
authors.initials: YS
authors.lastname: Huang
authors.forename: Yu-Yu
authors.initials: YY
authors.lastname: Wu
authors.forename: Philip
authors.initials: P
authors.lastname: Asherson
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000208:ethnology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005192:Family Health; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4; D013624:Taiwan; D020080:Tandem Repeat Sequences
chemical_list: C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4