But there are also fears that insurance companies could cash in on the advances by hiking premiums for those at risk - or even refusing to insure them altogether.
The discovery also raises the possibility that DIY genetic testing kits could be produced - allowing individuals a glimpse into their future health.
The latest findings centre around two research projects which, for the first time, have identified a common DNA sequence which greatly increases the risk of heart disease.
In the first study, Icelandic scientists compared the genetic make-up of 1,600 men and women who had heart attacks with almost 7,000 healthy people. They
discovered a particular stretch of DNA which greatly increased the risk of heart attacks - a conclusion they confirmed by screening the genes of thousands of Americans.
As all genetic sequences come in pairs - one inherited from the mother, the other from the father - the one in five people who carry two copies of the rogue strand of DNA are at greatest risk.
They are twice as likely to have a heart attack while still comparatively young - before the age of 50 for men and 60 for women - and 64 per cent more likely to have a heart attack at any age.
Those with one copy of the mutation are almost 50 per cent more likely to suffer an "early onset" heart attack than those with "normal" DNA and 26 per cent more likely to have a heart attack at any time.
The researchers, from Reykjavik biotechnology firm deCODE, calculated that the flawed DNA is behind almost a third of heart attacks in youngsters and a fifth of heart attacks overall.
They plan to create a test which would allow doctors to pinpoint those who are genetically programmed to suffer heart attacks.
The second study, carried out independently from the first, also picked out the same piece of DNA.
However the Canadian researchers, from the University of Ottawa calculated the risks as being slightly lower than the first set of scientists did.
They estimated that inheriting the genetic flaw increases the risk of heart disease - and strokes - by up to 40 per cent.
While both groups of scientists zeroed in on the same piece of DNA, it is not clear whether it forms a single gene or is part of several genes.
Alternatively, it may control nearby genes which are involved in cell growth, aging and death - all processes which play a role in the health of our circulation.
Even though it is not clear what the rogue DNA actually does, its discovery could pave the way for ways of treating and even preventing heart disease.
It also raises the possibility of creating genetic kits to test for the problem DNA.
However, experts warn the results of such tests are likely to be of little use until we can also test for other - as yet undiscovered - genes linked
to heart disease. Dr Helen Wallace, of watchdog GeneWatch UK, said genetic testing could give people the wrong impression about their chances of developing a disease.
She added that lack of regulation means companies could make also false claims about testing kits.
Experts stressed that while our genes are undoubtedly important in cardiac health, other factors such as smoking, poor diet and a lack of exercise play a much greater role in causing heart attacks.
Dr Tim Chico, a consultant cardiologist at Sheffield University, urged everyone to take control of their own health.
He said: "We must not forget that 90 per cent of the risk of heart attack comes from things like smoking, cholesterol, diet, lack of exercise and diabetes.
"The worst thing would be to think 'I haven't got this, so I'm safe', or 'I've got this, so I'm doomed'."
"The effect of smoking is double the effect of having this gene. If you smoke and are overweight and don't take enough exercise, that swamps the effect of your genes.
"Whatever our genetic make-up, we can all reduce our chances of heart disease by improving our lifestyle."
The breakthrough comes just weeks after scientists at Oxford University and the Peninsula Medical School in Exeter discovered an obesity gene.
The study revealed that the genetic make-up of one in six Britons increases their chance of becoming dangerously overweight by 70 per cent. |
