LONDON, April 29 (Xinhua) -- British scientists have
identified in a new study a gene that can cause the heart to become enlarged,
greatly increasing the risk of heart attacks and heart failure.
The new study, carried out by researchers from
Imperial College London, the British Medical Research Council and other
international institutions, suggested that the gene called osteoglycin (Ogn),
which had not previously been linked with heart function, can behave abnormally
in some people and can lead to the heart becoming abnormally enlarged, according
to a press release by Imperial College London on Tuesday.
The study showed that the osteoglycin gene regulates
the growth of the heart's main pumping chamber, its left ventricle. If the left
ventricle thickens, this creates a condition known as elevated Left Ventricular
Mass (LVM), a major contributing factor for common heart diseases. When the
heart is enlarged it needs more oxygen and becomes stiff. This can cause
shortness of breath or lead to a heart attack.
The researchers found that higher than normal levels
of Ogn were associated with the heart becoming enlarged in rats and mice and in
humans.
The researchers first linked the gene with elevated
LVM by looking at rat models and analyzing how LVM related to the genetic makeup
of rats with both elevated and normal LVM, then carried out the same analyzes on
samples from the human heart, volunteered by patients who had undergone cardiac
surgery at Hammersmith Hospital in UK and from a second group of patients from
the Netherlands.
These analyses showed that out of 22,000 possible
genes, osteoglycin was the gene most strongly correlated with elevated LVM in
humans.
Scientists believe that enlarged hearts are caused by
a combination of genetic factors and external stimuli such as high blood
pressure and obesity. However, the role played by genes has remained largely
unknown.
The researchers hope that through understanding how
enlarged hearts are linked to the workings of genes like Ogn, they will be able
to develop new treatments for the condition. They also hope that their findings
will provide new avenues for treating people who either have an enlarged heart
or are at risk of developing one. At present enlarged hearts can only be treated
by lowering blood pressure.
"Now that we are unravelling how genes control heart
growth, we can gain a better understanding of common forms of heart disease.
This should lead to new and more effective ways of treating people," Stuart
Cook, one of the corresponding authors of the study, said.
"This study shows how we can use the wealth of new
genome technologies for analyzing people's genes to gain a much greater
understanding of common human disorders. We already knew that enlarged hearts
were linked with conditions such as high blood pressure and obesity but figuring
out the genetic causes as well could be key to working out how to treat the
condition," Tim Aitman, another corresponding author of the study
said.