By Kevin Buckley

Genetic analysis could reveal heart risk

People with a malfunctioning LOX-1 gene appear to be almost three times more likely to suffer cardiac arrest.

"It would be wrong to say that LOX-1 is 'the' gene which, by itself, causes heart attacks," says Professor Jawahar Mehta, Director of the Division of Cardiovascular Medicine from the University of Arkansas for Medical Sciences.

"Our research in various countries, with diverse racial groups, appears to show that we have found something that is a universal gene abnormality which increases the risk of heart attacks.

"We are all very excited about it. It's a very serious advance."

We are all very excited about it - it's a very serious advance Professor Jawahar Mehta, University of Arkansas

The latest findings, presented at a recent meeting in Rome attended by American, Japanese and Italian researchers, open up the possibility of identifying carriers of a malfunctioning LOX-1 gene.

This could allow sufferers to take pre-emptive action through diet and lifestyle to combat their higher risk of heart trouble.

"In the longer term, with advances in genetics, the use of stem cells, it could be possible to eliminate this malfunction altogether," claims Professor Mehta, a scientist working in the USA for over 25 years.

Professor Guiseppe Novelli, a geneticist leading the Italian researchers at the Tor Vergata University on the outskirts of Rome and a collaborator of Professor Mehta, explains that LOX-1 was first discovered in 1997.

He said: "Heart attacks are not mono-causal.

"There is not one simple genetic cause.

"There are various factors involved, also including environmental and lifestyle factors. And various genes play different roles."

Researchers at Roche Pharmaceuticals are currently working on as many as 65 genes and up to 120 variants involved in cardiovascular disease.

'Furred' arteries

Cardiac arrest can occur when the interior walls of the arteries carrying blood supply to the heart become "furred up".

This narrowing and hardening of the arteries - atherosclerosis - impedes the normal blood flow to the crucial organ.

The dynamics of this process are complex, with approximately three dozen genes thought to play a part.

"Usually, when you refer to genes and the influence of a specific gene on a given condition, you are talking about a predictive value running at around 1.2, or 1.3," explains Professor Mehta.

This value represents the increased chance of the incidence of the condition, compared to the norm.

"With LOX-1, the predictive value is 3.74.

"If LOX-1 is not 'the' heart attack gene, it certainly is one of the most guilty parties."

Complex equation

However, geneticist Professor Novelli, in Rome, cautions: "For any particular individual it's difficult to assess exactly the respective influences played by varying environmental, lifestyle factors, such as smoking.

"Genetics certainly plays a fundamental role.

"In extreme cases, someone consuming great quantities of fats, could be protected by some variant in their DNA structure, which governs the way each gene operates.

"On the other hand, someone with a healthy lifestyle could have damaged arteries due to some unfavourable variant in their genetic code."

Far from being deleterious to health, the normal LOX-1 gene in fact plays a key part in the heart's defences says Professor Mehta.

But when, through some genetic mishap, LOX-1 goes into overdrive, it leads to the production of chemicals which can be damaging.