title: Association study of promoter polymorphisms at the dopamine transporter gene in Attention Deficit Hyperactivity Disorder.
abstract: BACKGROUND
  Attention deficit hyperactivity disorder (ADHD) is a complex neurobehavioral disorder. The dopamine transporter gene (DAT1/SLC6A3) has been considered a good candidate for ADHD. Most association studies with ADHD have investigated the 40-base-pair variable number of tandem repeat (VNTR) polymorphism in the 3'-untranslated region of DAT1. Only few studies have reported association between promoter polymorphisms of the gene and ADHD.
  
  
  METHODS
  To investigate the association between the polymorphisms -67A/T (rs2975226) and -839C/T (rs2652511) in promoter region of DAT1 in ADHD, two samples of ADHD patients from the UK (n = 197) and Taiwan (n = 212) were genotyped, and analysed using within-family transmission disequilibrium test (TDT).
  
  
  RESULTS
  A significant association was found between the T allele of promoter polymorphism -67A/T and ADHD in the Taiwanese population (P = 0.001). There was also evidence of preferential transmission of the T allele of -67A/T polymorphism in combined samples from the UK and Taiwan (P = 0.003). No association was detected between the -839C/T polymorphism and ADHD in either of the two populations.
  
  
  CONCLUSIONS
  The finding suggests that genetic variation in the promoter region of DAT1 may be a risk factor in the development of ADHD.
authors.affiliation: MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK. x.xu@iop.kcl.ac.uk
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
authors.forename: Jonathan
authors.initials: J
authors.lastname: Mill
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
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; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012307:Risk Factors
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins