Two groups have found rare gene mutations linked to reduced blood fat levels and a lower risk of heart disease.

The APOC3 gene codes for a protein that increases blood triglyceride levels — a known risk factor for heart disease. So, Anne Tybjaerg-Hansen at the Copenhagen University Hospital and her colleagues sequenced the protein-coding regions of the gene in more than 10,000 people and found three rare mutations associated with low blood triglyceride levels. They analysed these mutations in an additional 65,000 people and found that individuals with any of the mutations had a 36–41% lower risk of heart disease and stroke than people without any of the mutations.

Sekar Kathiresan at the Broad Institute in Cambridge, Massachusetts, and his team sequenced the protein-coding regions of nearly 20,000 genes from more than 3,500 participants and came up with four mutations in the same gene with similar effects.

The findings suggest that lowering blood triglyceride levels could protect against heart disease.

N. Engl. J. Med. http://doi.org/s98; http://doi.org/s97 (2014)