Researchers at the University of Texas Southwestern Medical Center in Dallas, have found by studying DNA from 11 members of one family, who suffered from aortic heart disease, a genetic mutation that causes a common birth defect and contributes to heart disease in adults.
They found that all five generations of the family including children and adults, had a mutation on a gene called NOTCH1.
Dr Vidu Garg, an assistant professor of pediatrics and molecular biology, says that mutations in NOTCH1 cause an early developmental defect in the aortic valve.
The researchers finding was confirmed, when they found a second mutation on the same gene in members of a smaller family in San Diego.
Normally the aortic valve is composed of three flaps of tissue that open and close to enable blood to flow in one direction, but a very small percent of the population are born with valves with only two flaps which make them susceptible to aortic valve stenosis.
This condition, which narrows the passage through which blood exits the heart, can require surgery at birth.
In severe cases the heart does not develop properly in the fetus and the child is born with an illness called hypoplastic left heart syndrome, which is a leading cause of heart disease deaths in children.
Dr Deepak Srivastava, of the University of California, San Francisco, who contributed to the research, says they know that aortic valve problems causes those deaths, but they now think NOTCH1 mutations are also likely to be the cause of some cases of hypoplastic left heart syndrome.
According to the scientists the finding could help to identify people at risk of the problem, and when researchers have a better understanding of the full impact of the mutation it could pave the way for new treatments for the heart ailments.
The finding is reported in the science journal Nature.http://www.swmed.edu/