Fu et al, studied exome sequencing data from 6,515 individual of European American and African American ancestry in order to define the age of Single Nucleotide Variants (SNVs) in the human genome. Using 6 different demographic models and based on a modified Out-of-Africa model, they estimated the age of all of the 1,146,601 identified SNVs. They estimate that approximately 73% of all the SNVs found in protein coding genes and the 86% of the ones predicted to be deleterious arose in the past 5,000-10,000 years. They conclude that the spectrum of protein-coding variation is significantly different between today and 200-400 generations ago and that this increase in rare functional variants led to a larger burden of Mendelian disorders but may have also created a new repository of advantageous alleles.
Periklis Makrythanasis, MD, PhD