Figure 1. CHRNA7 linkage disequilibrium (LD) plot.

The plot was generated by applying the Haploview program to genotype data from this study. The level of pairwise D', which indicates the degree of LD between two SNPs, is shown in the LD structure in gray scale. The level of pairwise r², which indicates the degree of correlation between two SNPs, is indicated by the number in the cell. Different numbers of common (frequency ≥5%) haplotypes were identified in each haplotype block. A modified Gabriel et al. algorithm was used to define the haplotype block [32], [33].