SNPwatch: Common SNP in Heart Attacks and Statin Effectiveness

SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason, it is important to remember that the studies we describe in SNPwatch are for informational and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.

One of the much-heralded claims of the post-genomic era is that personal genetic information may allow medical treatments to be tailored to an individual’s genetic makeup. While we are not there yet, a trio of new studies on heart disease may just have brought us one step closer. The studies were the product of a collaboration between researchers at Harvard Medical School and Celera (the company that helped spur completion of the public Human Genome Project).

In the first study of over 25,000 women, those with the GG or AG genotypes at the SNP were found to have a slightly increased chance of having a heart attack–about 34% higher than those with the AA genotype. (This study confirmed at least two other preliminary findings that this SNP, which is in the gene KIF6, is associated with heart disease.)

A second study of about 3,000 subjects further confirmed the first finding, and also examined whether the SNP was associated with the outcome of treatment with the cholesterol-lowering drug pravastatin. As other studies have reported, those with the GG or AG genotypes were found to be at higher risk of having a heart attack than those with the AA genotype. But when treated with pravastatin, the risk of heart attack for people with GG or AG was substantially reduced–approximately equal to that of the lower-risk AA group. (Pravastatin treatment had little or no effect on those with the AA genotype.)

Lastly, a third study of about 4,000 subjects compared how affected differences in outcomes for people given the standard-dose pravastatin therapy versus high-dose treatment with atorvastatin, another anti-cholesterol drug. Those with the AA genotype saw no additional benefit of receiving the more intense atorvastatin treatment compared to the standard pravastatin treatment. But people in the study with GG or AG did see a significant reduction in their risk of having a heart attack, cutting their risk by about 40% over two years.

Remember that genetics are only one factor that physicians may consider when prescribing preventive medications for heart disease or any condition. If you have concerns or questions about what you learn through 23andMe, you should contact your physician or other appropriate professional.