The quantile-quantile (QQ) plot of predicted and observed association results is presented in Fig. S3. The genomic inflation factor λ is 1.00, indicating that there is no bias of the test statistic. Figure 1 displays the P-values of association tests for the theta Fz phenotype in a Manhattan plot. The most significant results were located on chromosome 21, with seven SNPs reaching genome-wide significant P-values (see Table 1 for SNPs with p < 1 × 10−5). The SNP with the lowest P-value (4.7 × 10−10) was rs2835872 in KCNJ6 on chromosome 21. The G allele of rs2835872 was associated with lower theta power at Fz. This marker, along with 10 other SNPs listed in Table 1, were located within the introns of KCNJ6.
