A genetic mutation is associated with a change in a person's risk of heart disease from high to low — one of the first rare gene variants found, by sequencing large numbers of people, that has a sizable impact on disease risk.

Nicole Soranzo of the Wellcome Trust Sanger Institute in Hinxton and Nicholas Timpson of the University of Bristol, both in the United Kingdom, led a team that sequenced the genomes of 3,202 Europeans with known levels of blood triglycerides — fatty acids linked to increased risk of heart disease. They discovered that one variant of the APOC3 gene, found in less than 0.2% of the study participants, was associated with reductions in triglyceride levels that they estimated were large enough to significantly lower an individual's risk level.

The results support the idea that sequencing large populations can uncover rare genetic mutations that have a major impact on disease risk.

Nature Commun. 5, 4871 (2014)