rs20455

rs20455, often called Arg719 or 719Arg, is a reasonably well studied SNP in the KIF6 gene. The risk allele (encoding the arginine at position 719) is rs20455(C). An extensive 2010 meta-analysis, including over 17,000 patients, suggests this variant does not significantly influence coronary artery disease risk. This SNP is one of the 5 used by Celera's genetic risk score (GRS) for coronary heart disease (CHD). *rs20455, in the KIF6 gene *rs3900940, in the MYH15 gene *rs7439293, in the PALLD gene *rs2298566, in the SNX19 gene *rs1010, in the VAMP8 gene For each of the five variants, the GRS was increased by 1 if the subject was homozygous for the risk variant, unchanged if heterozygous, and decreased by 1 if the individual did not carry the variant. Therefore, individuals carrying all 10 possible risk variants (two copies of each of the five SNPs) were assigned a GRS of 5 and those carrying no risk variants a GRS of -5. A high GRS was defined as 3 or higher. Approximately 4% of the white cohort in ARIC was classified as high risk, and the hazard ratio for CHD after adjustment for traditional risk factors was a significant 1.57 (CI: 1.21-2.04; p<0.001). The results did not reproduce for African American participants. Carriers of the 719Arg allele of KIF6 have 34% higher risk of myocardial infarction and 24% higher risk of coronary heart disease compared with noncarriers among 25,283 women. Carriers of 719Arg receive significantly greater benefit from intensive statin therapy than do noncarriers. The benefit from intensive (compared with moderate) statin therapy was significantly greater in the 59% of the 1,778 patients who were carriers (hazard ratio 0.59, CI: 0.45 -0.77) than in those who were noncarriers (HR 0.94, CI: 0.70-1.27; p=0.018 for interaction between 719Arg carrier status and treatment). The absolute risk reduction was 10.0% in carriers versus 0.8% in noncarriers. Untreated carriers of the rs20455 risk allele had odds ratios for MI or stroke of 1.50 and 1.55 (CI: 1.05-2.15 or 1.14-2.09) in two large clinical trials. Among treated carriers, the absolute risk reduction by pravastatin therapy was 4.9% and 5.5% (CI: 1.81-7.9% or 3.5-7.5%). Therefore, in both trials carriers of a rs20455(C) SNP had an increased risk of coronary events, and statin treatment (in this case, pravastatin) reduced that risk more for such carriers than for noncarriers. Elderly carriers of a rs20455(C) (719Arg) allele with prior vascular disease received significant benefit from pravastatin; however, no benefit was observed in noncarriers with prior disease or in those without prior disease (carriers or noncarriers). Across all ethnic groups studied, pravastatin therapy significantly and substantially reduced both fatal coronary events and nonfatal myocardial infarctions only for carriers of the 719Arg allele (and not for noncarriers).