Researchers Discover Hair Loss Gene: 1 in 7 Men at Risk

News: Researchers Discover Baldness Gene: 1 in 7 Men at Risk

15 Oct 2008 Scientists at McGill, King's College and GSK solve mystery of male pattern baldness.

Researchers at McGill University, King's College London and GlaxoSmithKline Inc. have identified two genetic variants that, when both present in Caucasian men, increase the risk of male pattern baldness, also called male pattern alopecia, sevenfold. Their findings will be published in the 12 October edition of the journal Nature Genetics.

About a third of all men are affected by pattern baldness before age 45. The condition's social and economic impact is considerable: spending on hair transplants in the United States alone exceeded 115 million dollars in 2007, while global revenues for medical treatment for male pattern baldness recently surpassed 405 million dollars.

Male pattern baldness is the most common form of alopecia where hair is lost in a well-defined pattern beginning above both temples and receding to a distinctive M-shaped hairline. Estimates suggest that more than 80% 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 that a treatment or cure for male pattern baldness is imminent. ‘We've only identified one 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 is to first identify the cause.'

Researchers have long been aware of a genetic variant on the X chromosome that was linked to male pattern baldness. ‘That's where the idea that baldness is inherited from the mother's side of the family comes from,' the researcher explained. ‘However it's been long recognized that there must be several genes causing male pattern baldness. Until now, no one could identify those other genes. We now know that if a man has both the genetic variants we have discovered on chromosome 20 and the unrelated known variant on X chromosome, their risk of becoming bald is increased sevenfold. What's startling is that one in seven men has both of those risk variants. That's 14 per cent of the total population!'