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May 8, 2007: Researchers from US and
Europe have uncovered a gene that raises the
chance for heart disease--the leading cause of
death worldwide--occurring in around 60% of
people, reports the journal Science.
This rather common genetic variant is found in 50%
of Europeans. And some of them--about 20%--even
inherit two copies of the gene inherited from both
parents, it is found. It is much less prevalent in
people of African descent.
The new discovery would help to develop a test for
the variant to enable doctors to assess patients
at risk more accurately. So the doctors can
recommend susceptible patients to take adequate
precaution to lower risk factors like cholesterol,
blood pressure and so on.
The genetic variant is so common that some 50
percent of people in European populations carry
one copy of it, and about 20 percent of people
have inherited two copies, one from each parent.
The mechanism of genetic variation is yet to be
known. But carriers of a single copy have a 15
percent to 20 percent greater risk of heart
disease, while those with two copies are up to 60
percent more likely to develop heart disease than
people who have none. The risk is even higher for
people who suffer a heart attack at an early age,
defined as men under 50 and women under 60.
The discovery is a fruit of the $3 billion Human
Genome Project, which was essentially completed in
2003. DeCode Genetics, one of the firms involved
in this research, has used the comprehensive
health care records and known genealogy of the
Icelandic population to track disease. DeCode, a
private company based in Reykjavik, Iceland has
dominated the gene-finding field for the last
several years.
Other researchers are based at universities in the
United States and Europe. Both groups identified
snips in a small region of Chromosome 9 (the human
genome is packaged into 23 pairs) as being
associated with higher risk of heart disease.
But as if to prove how much remains to be
understood about human biology, the snips lie in a
stretch of DNA that contains no gene or genetic
element with known functional purpose. It is only
on the basis of rigorous statistics that the two
groups believe their snips must be causally
associated with heart disease. They have been
helped by a technical development, the
construction by companies like Affymetrix and
Illumina of instruments known as microarrays or
chips.
The variant lies at a site on Chromosome 9 very
close to one of the diabetes variants. Biologists
suggested the link hinted at an unsuspected common
biology between the two diseases.
BY OUR PHARMA CORRESPONDENT
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