It is important to understand that there are a number of different genes that can affect the development of coronary disease. There are certain metabolic disorders of the liver that can lead to high cholesterol and blockages in vessels. And certain genetic defects can result in a higher likelihood for blood clotting, raising the risks for heart attacks. For each involved gene, there can be a wide variety of slight changes in the chemical structure of the gene known as single nucleotide polymorphisms. Some of these changes can raise one's risk for coronary disease while others may be protective against the disease, according to Dr Selvamurthy, a reknowned physiologist and a close associate of APJ Abdul Kalam, the president of India.

Dr Soma Raju, chairman, Care Hospitals, said, researchers have identified more than 250 genes that may play a role in coronary artery disease (CAD). It is observed in most cases, CAD is not inherited in a clearly dominant or recessive manner. A person may have mutations in some genes that increase risk and mutations in other genes that decrease risk. On an average, a person's risk level is approximately midway between those of the parents.

Prof P Krishnam Raju, chairman, CARE Foundation, said that each person's genetic risk for hypertension and coronary artery disease is determined by the combined effects of many genes and could be the starting point to establish the significance of the disorders in these genes, leading to coronary artery disease.

They were speaking at the inauguration of a new genetic diagnostic laboratory at Care Hospitals, Hyderabad on Friday, last week.