Fig. 1.

Linkage disequilibrium (LD) analyses of selected 7 positionally only relevant genes which was focused in 18q21 fine mapping research. Twenty single nucleotide polymorphisms (SNPs) genotyped in our fine mapping for methamphetamine abusers and controls are also represented. Haplotype block pattern constructed by the Haploview program (Barrett et al. 2005) is shown. The number in each cell represents the LD. Parameter D' (×100), blank cells mean D'=1. Each cell is painted with graduated color relative to the strength of LD between markers, which is defined by both D' value and confidence bounds on D'. SNPs are indicated by a SNP ID number (rs number).