Researchers from the University of Washington and elsewhere turned to exome sequencing data collected by the National Heart, Lung, and Blood Institute Exome Sequencing Project to gauge just how often incidental findings would be uncovered in a population, as they report in the American Journal of Human Genetics.
For this group of 2,204 African Americans and 4,313 European Americans, UW's Michael Bamshad and colleagues examined the frequency of pathogenic alleles in some 70 genes, including ones usually tested as part of newborn screening, ones linked to age-related macular degeneration, and ones that influence drug response.
They found that each individual harbored a mean 15.3 risk alleles, including at least five pharmacogenomics alleles, and most everyone had at least one age-related macular degeneration risk allele.
"These findings challenge the assumption that secondary findings (actionable results) and incidental findings (potential clinical utility) uncovered by exome or genome sequencing are rare," says Dan Koboldt at his MassGenomics blog.
Indeed, the researchers say that their findings indicate that everyone's genome likely harbors a variant of clinical utility.