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Hair Loss News Archives
October 2008
Discovery Of Baldness Gene: 1 In 7 Men At Risk
Oct 2008
Researchers at McGill University, King's College London and GlaxoSmithKline Inc. have identified two genetic variants in caucasians that together produce an astounding sevenfold increase in the risk of male pattern baldness.
Two studies released today in the journal Nature Genetics may help explain
why some people lose their hair, and how they might eventually grow it back,
scientists from London-based GlaxoSmithKline, the U.K. and Sweden said.
About a third of all men are affected by male pattern baldness by age 45. The
condition's social and economic impact is considerable: expenditures for hair
transplantation in the United States alone exceeded $115 million (U.S.) in 2007,
while global revenues for medical therapy for male-pattern baldness recently
surpassed $405 million.
Male pattern baldness is the most common form of baldness, where hair is lost
in a well-defined pattern beginning above both temples, and results in a
distinctive M-shaped hairline. Estimates suggest more than 80 per cent of cases
are hereditary.
This study was conducted by Dr. Vincent Mooser of GlaxoSmithKline, Dr. Brent
Richards of McGill University's Faculty of Medicine and the affiliated Jewish
General Hospital (and formerly of King's College), and Dr. Tim Spector of King's
College.
Along with colleagues in Iceland, Switzerland and the Netherlands, the researchers conducted a genome-wide association study of 1,125 caucasian men who had been assessed for male pattern baldness.
They found two previously unknown genetic variants on chromosome 20 that
substantially increased the risk of male pattern baldness. They then confirmed
these findings in an additional 1,650 caucasian men.
"I would presume male pattern baldness is caused by the same genetic variation
in non-caucasians," said Richards, an assistant professor in genetic
epidemiology, "but we haven't studied those populations, so we can't say for
certain."
Though the researchers consider their discovery to be a scientific breakthrough,
they caution that it does not mean a treatment or cure for male pattern baldness
is imminent.
"We've only identified a cause," Richards said. "Treating male pattern baldness
will require more research. But, of course, the first step in finding a way to
treat most conditions it is to first identify the cause."
"Early prediction before hair loss starts may lead to some interesting therapies
that are more effective than treating late stage hair loss," added Spector, of
King's College and director of the TwinsUK cohort study.
Researchers have long been aware of a genetic variant on the X chromosome that
was linked to male pattern baldness, Richards said.
"That's where the idea that baldness is inherited from the mother's side of the
family comes from," he explained. "However it's been long recognized that that
there must be several genes causing male pattern baldness. Until now, no one
could identify those other genes.
If you have both the risk variants we discovered on chromosome 20 and the
unrelated known variant on the X chromosome, your risk of becoming bald
increases sevenfold."
"What's startling is that one in seven men have both of those risk variants.
That's 14 per cent of the total population!"