First Cross-Race Genetic Link to Arterial Diseases, Heart Attacks Found
A
year ago, researchers found that a cluster of genetic variants on a specific
region of chromosome 9 is linked to coronary artery disease (CAD) in white
people in northern Europe and North America . People who have that genetic
quirk are more susceptible to developing CAD or having a heart attack.
Now, Lerner Research Institute researchers have shown the same genetic material also is associated with coronary artery diseases in the South Korean population – the first evidence of cross-race susceptibility to CAD associated with the same specific combination of genetic variants.
CAD is a condition in which plaque builds up inside the coronary arteries that supply heart muscle with oxygen-rich blood. Plaque narrows the coronary arteries and reduces blood flow to heart muscle. It also makes it more likely that blood clots will form in arteries. CAD can lead to angina, heart attack, heart failure, and arrhythmias (irregular heartbeats). It is the most common type of heart disease and the leading cause of death in the United States for both men and women. Both genetic and environmental factors – and the interplay between the two – have been identified as major risk factors for people developing CAD. But the molecules and genes that contribute to the genetic risk have remained largely unidentified.
At the center of the research are four single nucleotide polymorphisms (or SNPs) that are at a specific location on the 9p21 piece of chromosome 9. Each SNP is a single DNA building block. SNPs occur normally throughout a person's DNA, which means there are roughly 10 million SNPs in the human genome. Most SNPs have no effect on health or development. But when SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene's function.
In this case, the presence of these four SNPs on 9p21 seem to be associated with CAD, meaning people who have these four specific SNPs on their 9p21 gene have a higher risk of developing coronary disease or suffering a heart attack.
Research led by Qing Wang, PhD, of the Institute's Department of Molecular Cardiology and Director of the Center for Cardiovascular Genetics, took what is known about the 9p21 SNPs in the white population and applied it to 611 South Koreans who were diagnosed with CAD and 294 healthy control patients.
The researchers found a similar association between the 9p21 SNPs and a higher risk of developing coronary disease and suffering heart attacks among Asians.
“Identifying specific ‘hot spots' that might harbor one or more genes that could influence development of CAD and showing that it is a cross-race risk is an important advance in being able to genetically screen for coronary and arterial diseases or heart attacks,” Dr. Wang said. “Proving this association across diverse human populations can lead to new clinical markers for disease which can alert people about their risk of CAD or heart attack years before any actual diseases develop. Early screening can lead to people making lifestyles changes to reduce the risk and earlier monitoring for potential health problems.”
Dr. Wang's team included Gong-Qing Shen, MD, PhD, Lin Li, PhD, Shaoqi Rao, PhD, and Kalil G. Abdullah, all in Molecular Cardiology. Collaborating on the research were Ji Min Ban, Bok-Soo Lee, PhD, and Jeong Euy Park, MD, of the Samsung Medical Center in Seoul , South Korea . The findings recently appeared in the journal Arteriosclerosis, Thrombosis, and Vascular Biology ( http://atvb.ahajournals.org/, 2008;28;360-365).