2000 common variations and counting

Over the past five years, genome-wide association studies (GWAS) have identified about 2,000 common genetic variations that underlie human disease risk. Earlier this week, we told you about a model Broad researchers and collaborators developed to help explain how thousands of other common genetic variations with low effect size combine to contribute to disease risk in rheumatoid arthritis and three other common diseases with a known genetic link. See the news story and the original paper published in Nature Genetics.

In my research for the Broad’s news story, I was visually delighted to come across a beautiful graphic from the National Human Genome Research Institute displaying the known network of approximately 1,500 genetic variations known as single nucleotide polymorphisms (SNPs) identified through GWAS as of mid-2011.

This image captures the breadth and precision of GWAS, how they have unveiled these thousands of human genetic secrets since the first studies were published in 2005. In just six years, researchers have identified genetic variations across chromosomes 1-22 and the X chromosome and contributing to diseases or traits ranging from abdominal aortic aneurysm to YKL-40 levels.

As cool as this image is, it doesn’t tell the whole story – yet. With new tools like the statistical model we shared this week, researchers may able to add thousands of common variants that were previously below the threshold of detection. As the list grows, more and more of the once “hidden heritability” of certain diseases will be revealed.