Nature Genetics article details 12 new genes, including variants in PCSK9 gene that affect cholesterol.
In a study claimed to be the most detailed assessment of the genetics of cholesterol to date, scientists examining genetic variants and cholesterol levels in more than 40,000 individuals have identified 12 new genes that relate to cholesterol and glucose levels, several of which point to surprising links between these traits and other conditions. For instance, some of the genes link gallstones and blood cholesterol levels, while others link melatonin and sleep patterns to small increases in glucose levels and larger jumps in the risk of diabetes.
In the PCSK9 gene alone there are common variants that affect about 40% of the population and increase LDL by about 3–6 milligrams per deciliter. Another variant affects roughly 2% of individuals but increases LDL by about 15–30 milligrams per deciliter. Finally, there are extremely rare changes in the same gene that affect fewer than 1 in 1000 people but can increase LDL by well over 100 milligrams per deciliter.
In a previous study, the research team had shown that genetic variants that raise LDL cholesterol levels also increase the risk of heart disease. Now investigators have looked at the genomes of 36,000 individuals to locate 30 genetic variants associated with cholesterol levels. Several of the newly implicated genetic variants were also related to the risk of gallstones and certain rare forms of diabetes.
In the paper studying glucose levels, researchers helped discover genetic changes strongly associated with a small increase in glucose levels in nondiabetic individuals. They also found the same changes increased the risk of developing diabetes by up to 20 %.
The gene, called the melatonin receptor, helps regulate the circadian clock, among other things. The finding strengthens the association between disrupted sleep patterns and diabetes, according to the researchers.
Nature Genetics published two papers explaining the findings online December 7. Scientists in the study conduct research at the University of Michigan School of Public Health, Massachusetts General Hospital, and Harvard Medical School.