Haplotype variation and linkage disequilibrium in 313 human genes

Variation within genes has important implications for all biological traits . We identified 3899 single nucleotide polymorphisms (SNPs) that were prese nt within 313 genes from 82 unrelated individuals of diverse ancestry, and we organized the SNPs into 4304 different haplotypes. Each gene had several variable SNPs and haplotypes that were present in all populations, as well as a number that were population-specific. Pairs of SNPs exhibited variabi lity in the degree of Linkage disequilibrium that was a function of their L ocation within a gene, distance from each other, population distribution, a nd population frequency. Haplotypes generally had more information content (heterozygosity) than did individual SNPs. Our analysis of the pattern of v ariation strongly supports the recent expansion of the human population.