QUEBEC CITY, Oct. 22 /CNW Telbec/ - A team led by a Heart and Stroke
Foundation researcher has uncovered a series of genes linking mental stress,
high blood pressure, alcoholism and tobacco addiction.
Discovering and mapping these genetic pathways leading to major heart
disease and stroke risk factors is the latest breakthrough from ongoing
studies in the Saguenay-Lac St. Jean region of Quebec.
"Our results remind us that we are lucky that biology is not entirely
destiny," team director Dr. Pavel Hamet told the Canadian Cardiovascular
Congress 2007, co-hosted by the Heart and Stroke Foundation and the Canadian
"Fortunately, one's genetic inheritance consequences can be modified to a
significant extent by living a heart-healthy lifestyle," says Dr. Hamet.
The most recent studies from the Saguenay focus on sexual differences and
alcoholism. "The genes we discovered that govern alcohol intake appear on
chromosome X," says Dr. Hamet.
Male cells have only one chromosome X. So males are more at risk than
women (who have two). "This may explain why males are more prone to alcohol
abuse," he says. "Our research indicates that when the father is affected,
half of the siblings will be affected, but when the mother is affected three
quarters of the siblings will be affected," he noted.
"On the other hand, when parents are not affected, one quarter of the
siblings still can be, depending on the environment."
According to Dr. Hamet, there is no reason to believe that people from
the Saguenay have higher rates of stress, high blood pressure, alcoholism, or
tobacco addiction, but the genes that cause these conditions are easier to
find because family histories are so well documented.
"The Saguenay studies are allowing us to take the first steps in
individualized, predictive genomics," said Dr. Hamet. That means better
targeted treatments for all Canadians.
"For example, knowing that there is a gene that produces the symptoms we
associate with mental stress means we can bypass the expression of that gene
by avoiding stress-provoking situations," he says. And for some people, there
is a definite behavioural component to high blood pressure. "These are the
patients who respond well to exercise and lifestyle changes," says Dr. Hamet.
The inhabitants of Saguenay Lac St. Jean have been making a unique
contribution to medical genetics for over a decade.
The area has been relatively isolated from the rest of Quebec and Canada.
The region was occupied in three waves in the 17th century by settlers from
France. Many families live on their original farms or work at the same trades
as their ancestors.
Large families were the norm and until the early 1960s it was not unusual
for families to have up to 12 children - a remarkable expansion of the
original genome. In addition, their genealogies (family trees) have been
computerized, including cause of death whenever present.
"This information from family records indicates to us the families where
a common cause of disability showed up in several generations," says
Dr. Hamet. "By studying the modern descendants we can find candidate genes for
"People are still debating whether illnesses are all in the genes or all
in the environment. Neither is true. It is all in the interaction between the
two. And you can modulate the impact of the genes by modulating the
The study was presented by Majid Nikpay. He is funded by the Heart and
Stroke Foundation of Canada and the Canadian Institutes of Health Research
through the GENESIS ICE Team.
This study is co-funded by the Heart and Stroke Foundation of Canada and
the Canadian Institutes of Health Research Institute of Circulatory and
Statements and conclusions of study authors are solely those of the study
authors and do not necessarily reflect Foundation policy or position. The
Heart and Stroke Foundation of Canada makes no representation or warranty as
to their accuracy or reliability.
The Heart and Stroke Foundation (www.heartandstroke.ca), a
volunteer-based health charity, leads in eliminating heart disease and stroke
and reducing their impact through the advancement of research and its
application, the promotion of healthy living, and advocacy.
For further information:
For further information: and/or interviews, contact the CCC 2007 media
office, (418) 649-5215 (Oct 21-24); Marie-Christine Garon, Massy-Forget Public
Relations, (514) 842-2455 ext. 23, firstname.lastname@example.org; Congress information and
media registration at www.cardiocongress.org; After October 24, 2007,
Jane-Diane Fraser, Heart and Stroke Foundation of Canada, (613) 569-4361 ext