A Deep Look Into Our Genes Recent debates have focused on the degree of genetic variation and its impact upon health at the genomic level in humans (see the Perspective by Casals and Bertranpetit ). Tennessen et al. (p. 64 , published online 17 May), looking at all of the protein-coding genes in the human genome, and Nelson et al. (p. 100 , published online 17 May), looking at genes that encode drug targets, address this question through deep sequencing efforts on samples from multiple individuals. The findings suggest that most human variation is rare, not shared between populations, and that rare variants are likely to play a role in human health.

Evolution and Functional Impact of Rare Coding Variation from Deep Sequencing of Human Exomes