Figure 1

NGFR gene linkage disequilibrium (LD) plot. The plot was generated by genotype data from this study by HaploView program. The level of pairwise D', which indicated the degree of linkage disequilibrium between two SNPs, was shown in the linkage disequilibrium structure in gray scale. The level of pairwise r², which indicated the degree of correlation between two SNPs, was the number in the cell of the LD plot. Five common (frequency ≧ 5%) haplotypes were identified. Modified Gabriel et al. algorithm was used to define the haplotype block and 5 htSNPs formed one block.