Digital Quantification of Human Eye Color Highlights Genetic Association of Three New Loci
Observed −log10 P values in a GWA of CHS1 are ranked on the y-axis and plotted against the expected distribution under the null on the x-axis. All P values smaller than 10−10 were truncated at 10 at the log scale. The red dots are the P values excluding the effects of sex, age, and population stratification. Blue dots are the P values excluding the effects of 7 genes previously known to be involved in eye color. Green dots are the P values after additionally excluding the effects of 3 newly identified loci, with no more SNPs showing significant association at the genome-wide level.