Race, Genetics and Cardiovascular Disease

Abstract

Significant strides from personalized medicine hold great promise to improve early detection, guide targeted therapies, and enhance disease monitoring while simultaneously incorporating specific contributions from race and ethnicity in disease pathogenesis. Hypertension underscores complex gene–environment interactions related to salt sensitivity. Genetic disorders in which certain candidate genes result in a loss of function and the aberrant expression of an abnormal gene product might give rise to either autosomal dominant or recessive inheritance patters. For example, impaired vascular function has been reported in both healthy and hypertensive African Americans. To account for ethnic differences in cardiovascular disease prevalence and outcome, however, the bioavailability of nitric oxide has been proposed as one mechanism to explain difference in vascular function. Alteration of nitric oxide production has been linked to olymorphisms in the gene encoding the endothelial nitric oxide synthase (ecNOS) in African Americans.

Distinctive variations, either by gender or by ethnicity, in the prevalence of significant CAD and mortality are often attributed to provider bias, in equities in heath care access or both. In spite of the earlier literature showing gaps by gender or ethnicity for heath-care access and treatment, direct evidence that disparities might be explained only by biases is lacking. Investigations such as the African-American Heart Failure Trial (A-HeFT) may now serve as a powerful reminder for us to avoid similar missed opportunities to explore emerging disciplines such as pharmacogenetics in the genomic era. Future guidelines on beta-adrenergic blockade for patients with heart failure or cardiac ischemia will inevitably be revised when the genetic information is available utilizing pharmacogenetics. Specific knowledge of an individual’s genetic composition will eliminate existing proxies using skin color for phenotyping disease susceptibility or resistance while enabling adequate monitoring and surveillance measures to be instituted.