Here’s what we told the world’s journalists last week. You can use Google News to see what they made of our briefing.
Please cite Nature Genetics as the source of the following items. If publishing online, please carry a hyperlink to https://www.nature.com/naturegenetics.
Genetic variant associated with triglyceride levels
Scientists have identified a rare genetic variant that is associated with lower levels of triglycerides, according to a study to be published online this week in Nature Genetics. Triglycerides are the stored form of fat, and elevated levels have been linked to risk of coronary artery disease.
The genetic contribution to common diseases takes the form of common variants – those found at frequencies greater than 5% – and rare variants. One strategy to identify rare variants is to resequence candidate genes in a number of individuals. Jonathan Cohen and colleagues report the first application of this strategy in a large population. The authors studied more than 3,500 individuals from the Dallas Heart Study, whose lipid and glucose metabolism has been characterized in detail. They sequenced the gene ANGPTL4, which encodes a hormone involved in lipid metabolism, in each of these individuals. They found that those individuals with the lowest levels of triglycerides had more variation in ANGPTL4, and one variant in particular was associated with a 27% reduction in triglyceride levels, compared with individuals who lack the variant.
This association was confirmed in two other large population-based studies. Overall, this study confirms the value of the resequencing approach in identifying genetic variants that influence disease-related traits.
Genetic variant associated with protection against infectious diseases
A genetic variant associated with protection against four different infectious diseases is described in an online study this week in Nature Genetics. The variant, which is significantly more likely to be found in individuals who remain disease-free, is estimated to reduce the risk of disease by approximately half.
Proteins called ‘toll-like receptors’ (TLRs) are involved in the immune response to a variety of pathogens. Adrian Hill and colleagues reasoned that variation in a protein called Mal, which is a critical mediator of signaling by TLRs, might make certain individuals more or less susceptible to infectious disease. The authors determined the frequency of 33 single-nucleotide variants in the gene encoding Mal in more than 6,000 individuals from Gambia, Kenya, the UK and Vietnam with or without pneumococcal disease, bacteremia, malaria and tuberculosis – diseases that account for more than 5 million deaths each year in the developing world.