Family-based association study of serotonin transporter gene polymorphisms in attention deficit hyperactivity disorder: no evidence for association in UK and Taiwanese samples

Am J Med Genet B Neuropsychiatr Genet. 2005 Nov 5;139B(1):11-3. doi: 10.1002/ajmg.b.30203.


Five independent studies have reported associations between serotonin transporter gene (5-HTT) polymorphisms and attention deficit hyperactivity disorder (ADHD). Four studies found evidence for association between the long-allele of a 44-base pair insertion/deletion polymorphism (5-HTTLPR), one of the studies found association to a variable number tandem repeat within intron 2, another to the T-allele of a single base pair substitution in the 3'-untranslated regions and another reported preferential transmission of a haplotype of the three markers (long-allele/10-repeat-allele/T-allele). One further study found no evidence for these associations. We investigated the association of these three markers in two samples of ADHD patients from the United Kingdom (n = 197) and Taiwan (n = 212), using within-family tests of association. No association was found between any of the three markers in either of the two populations. Although we found some evidence for the preferential transmission of a rare haplotype (long-allele/9-repeat-allele/T-allele; chi2 = 4.5, P = 0.034), we concluded that this most likely occurred by chance factors alone.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Attention Deficit Disorder with Hyperactivity / genetics*
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Female
  • Genotype
  • Haplotypes
  • Humans
  • Male
  • Polymorphism, Genetic*
  • Promoter Regions, Genetic
  • Serotonin Plasma Membrane Transport Proteins / genetics*
  • Taiwan
  • United Kingdom


  • Serotonin Plasma Membrane Transport Proteins