Researchers at a Utah-based company said Tuesday that they had discovered a gene linked with heart disease--the first such gene to be positively identified.
The gene, named CHD1 for coronary heart disease, affected about 10% of the families with experience of heart disease at an early age who were studied by researchers at Salt Lake City-based Myriad Genetics.
"This is the first gene discovery in the cardiovascular disease area," said Dennis Ballinger, director of coronary heart disease research at Myriad.
The gene probably acts along with diet and exercise--or a lack of exercise--to cause heart disease, Ballinger said.
Myriad, working with Novartis Pharmaceuticals Corp., a unit of the Swiss drug giant, and the University of Utah, has patented the gene.
The next step, Ballinger said, is to find out what the gene does. "It looks like it's identified a novel pathway that hasn't been identified before for coronary heart disease," he said.
Researchers would have to grow cells with the specific mutation they found and see what the cells did. Then they would see if a drug could be developed.
Ballinger said Myriad took advantage of the extensive family records kept by officials in Utah, especially the Mormon Church, to trace 75 families who had "clusters" of early coronary heart disease.
This is defined as coronary heart disease before age 50 in men and 55 in women. Sufferers had clogged arteries, heart attacks or had undergone coronary artery bypass surgery. There also was a family tendency to obesity and diabetes.
"Then we looked for regions of the chromosomes that were shared among the affected individuals," Ballinger said.
"We found a region of the chromosome that is held in common among affected individuals in about eight of those families. In the region that was so defined we found a gene that we think from biology and from these linkage studies appears to be involved in CHD."
One amino acid, the basic component of genetic material, is mutated in the people affected, Ballinger said.
He said little was known about what exactly it did and declined any comment on what the company did know. Every gene in the body controls production of a protein, and a new protein never seen before seems to be coded by CHD1.
Ballinger admitted that the gene was unlikely to be a major cause of heart disease. "We haven't done careful population studies to know exactly what the incidence is," he said.
Myriad discovers and patents genes, and works with drug companies to develop their findings.
Experts say there is a growing body of evidence that genes are strongly involved in heart disease, which is why some people can smoke and overeat with no ill effects but most succumb to cancer and heart disease.
Researchers at the University of California's Lawrence Berkeley National Laboratory say the apoE4 gene, linked with Alzheimer's disease, also may be involved in heart disease.