London, Oct 13 : An international team of researchers has found that two genetic variants that may put men at a sevenfold increased risk of male pattern baldness.
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.
In the study conducted over Caucasians, researchers at McGill University, King's College London and GlaxoSmithKline Inc have identified two previously unknown genetic variants on chromosome 20 that can significantly raise the risk of male pattern baldness.
"I would presume male pattern baldness is caused by the same genetic variation in non-caucasians," Nature Genetics quoted Brent Richards of McGill University's Faculty of Medicine and the affiliated Jewish General Hospital, as saying.
But we haven't studied those populations, so we can't say for certain," he added.
For the study, the researchers analysed 1,125 Caucasian men who had been assessed for male pattern baldness.
They cautioned that it does not mean a treatment or cure for male pattern baldness.
"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," he added.
"Early prediction before hair loss starts may lead to some interesting therapies that are more effective than treating late stage hair loss," added Dr. Tim Spector, of King's College and director of the TwinsUK cohort study.
Previous studies have linked genetic variant on the X chromosome to male pattern baldness.
"That's where the idea that baldness is inherited from the mother's side of the family comes from," he said.
"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!" he added.
The study appears in Nature Genetics.