Searching for functional SNPs or rare variants in exonic regions of DRD3 in risperidone-treated patients

Previously one intronic DRD3 SNP, rs167771, was associated with risperidone-induced extrapyramidal side-effects (EPS). The aim of the present study was to search hitherto unidentified common functional variants or rare variants, in DRD3 associated with risperidone-induced EPS. 126 subjects treated with risperidone participated in this study. We sequenced the seven exons of DRD3. After sequencing we localized five dbSNPs and four new rare variants. None of the dSNPs or rare variants seems to be functional after bioinformatics analysis. Our results suggest that, rather than exonic regions, regulatory regions and introns could be related to the associations reported for DRD3 and the incidence of locomotor side-effects.