Single-nucleotide polymorphism (SNP) selection

To capture most common polymorphisms in DRD2, seven tag SNPs (rs4938019, rs4245148, rs4648319, rs4436578, rs7122246, rs1076560, and rs6279) were first selected from HapMap (http://hapmap.ncbi.nlm.nih.gov) genotype data for the Han Chinese population in Beijing (CHB) (Data Rel 27 Phase II + III, Feb09, on National Center for Biotechnology Information B36 assembly, dbSNP b126) by applying the Tagger program as implemented in Haploview (Version 4.2) software (Barrett et al., 2005) with the following criteria: pairwise tagging only, r² > 0.80 and minor allele frequency (MAF) > 5%. The seven selected tag SNP captured 59 out of 66 (89%) common alleles (MAF > 5%) of the genomic region of DRD2 (chr11: 112785528.112851091, based on National Center for Biotechnology Information Genome Build 36.3), with a mean maximal r² = 0.95. In addition, eight putative functional SNPs (rs1799978, rs1799732, rs4648317, rs2283265, rs6277, rs6276 and rs6278, and rs1800497) were also genotyped. Table ​Table11 summarizes the final set of genotyped SNPs.

Characteristics of the Genotyped SNPs.

HWE, Hardy–Weinberg equilibrium; MAF, minor allele frequency; UTR, untranslated region.