It has been known to medical science for years now that genes, together with environmental factors, increase the risk of people developing health problems including heart disease. However they haven??t yet been able to decipher exactly which parts of the genome are responsible in increasing the risk. The genome covers the total collection of DNA including the genes and other genetic material.
For the new study, researchers at the University of Leicester led by Dr. Nilesh Samani analysed more than 500,000 genetic changes in around 5,000 people. These included 2,000 white Europeans with coronary artery disease and 3,000 healthy people.
The researchers used results from a similar German study to draw comparisons and identify the common genetic variations that led to an increase in the risk for heart disease. They found that changes in the DNA on the chromosomes were responsible for increased risk of developing coronary artery disease and heart attacks. The researchers identified not one or two but six different genetic variations, each linked to a higher risk.
The findings by Dr. Samani and team confirm those of a study earlier this year in which researchers found that mutations on another chromosome increased the risk of heart disease. ??Carrying one copy of the genetic change increased the chance of developing heart disease by at least 20 percent, while two copies increased the risk by more than 40 percent? Dr. Samani said.
??Understanding the genetics that lead to heart disease is a powerful tool to tell us how much risk a person faces,? he said. ??We are not talking about rare genetic variants here, but rather variants that are very common in our population.?
The researchers believe their findings add to already accumulating proof that can help explain the reason behind many people suffering heart disease even without displaying any clear risk factors such as smoking, high cholesterol or high blood pressure. ??The research could also pave the way for more effective drugs and better treatment and screening,? Dr. Samani said.
??People have identified genetic variants which change risk but this is the best evidence of specific markers,? Dr. Samani said about their study which has been published in the New England Journal of Medicine. In his opinion, the next step requires studying larger groups to identify how genetic mutations fitted in with other risk factors such as high cholesterol.