A Common Variant in DRD3 Receptor Is Associated with Autism Spectrum Disorder

Background The presence of specific and common genetic etiologies for autism spectrum disorders (ASD) and attention-deficit/hyperactivity disorder (ADHD) was investigated for 132 candidate genes in a two-stage design-association study. Methods 1,536 single nucleotide polymorphisms (SNPs) covering these candidate genes were tested in ASD ( n = 144) and ADHD ( n = 110) patients and control subjects ( n = 404) from The Netherlands. A second stage was performed with those SNPs from Stage I reaching a significance threshold for association of p < .01 in an independent sample of ASD patients ( n = 128) and controls ( n = 124) from the United Kingdom and a Dutch ADHD ( n = 150) and control ( n = 149) sample. Results No shared association was found between ASD and ADHD. However, in the first and second ASD samples and in a joint statistical analysis, a significant association between SNP rs167771 located in the DRD3 gene was found (joint analysis uncorrected: p = 3.11 × 10−6 ; corrected for multiple testing and potential stratification: p = .00162). Conclusions The DRD3 gene is related to stereotyped behavior, liability to side effects of antipsychotic medication, and movement disorders and may therefore have important clinical implications for ASD.