An LDLR missense variant poses high risk of familial hypercholesterolemia in 30% of Greenlanders and offers potential for early cardiovascular disease intervention

Background: The common Arctic specific LDLR p.G137S variant was recently shown to be associated with elevated lipid levels. Motivated by this we aimed to investigate the effect of p.G137S on metabolic health, and cardiovascular disease risk among Greenlanders to quantify its impact on the population. Methods: In a population based Greenlandic cohort (n=5063), we tested for associations between the p.G137S variant and metabolic health traits as well as cardiovascular disease risk based on registry data. Additionally, we explored the variant's impact on plasma NMR measured lipoprotein concentration and composition in another Greenlandic cohort (n=1629). Results: 29.5% of the individuals in the cohort carried at least one copy of the p.G137S risk allele. Furthermore, 25.4% of the heterozygous and 54.7% of the homozygous carriers had high levels (>4.9 mmol/L) of LDL cholesterol, which is above the diagnostic level for familial hypercholesterolemia (FH). Moreover, p.G137S was associated with an overall atherosclerotic lipid profile, and increased risk of ischaemic heart disease (HR (95% CI), 1.51 (1.18-1.92), P=0.00096), peripheral artery disease (1.69 (1.01-2.82), P=0.046), and coronary operations (1.78 (1.21-2.62), P=0.0035). Conclusions: Due to its high frequency and large effect sizes, p.G137S has a marked population-level impact, increasing the risk of FH and cardiovascular disease for up to 30% of the Greenlandic population. Thus, p.G137S is a potential marker for early intervention in Arctic populations.