By Melinda Wenner Moyer
In the past five years, scientists have identified more than 3,000 common genetic mutations associated with diseases including cancer, Alzheimer’s and diabetes, thanks to insights gleaned from genome-wide association studies (GWASs). But the inherent value of these studies has come under scrutiny, in part because they largely ignore rare mutations. Given this flaw, researchers have called for renewed focus on the rare mutations that might be more likely than common ones to cause illness.
The GWAS approach involves comparing the genomes of healthy people with those suffering from illness to pinpoint disease-associated single nucleotide polymorphisms (SNPs) typically present in at least 5% of the population. “A GWAS study is meant to capture most of the common variation in the genome, and that’s something it does very well,” says Jonathan Sebat, a geneticist at the University of California–San Diego. (Click here to continue reading)