Researchers discover baldness gene: 1 in 7 men at risk
Scientists at 平特五不中, King鈥檚 College and GSK solve mystery of male pattern baldness
Researchers at 平特五不中, King鈥檚 College London and GlaxoSmithKline Inc. have identified two genetic variants in caucasians that together produce an astounding sevenfold increase the risk of male pattern baldness. Their results will be published Oct. 12 in the journal Nature Genetics.
About a third of all men are affected by male pattern baldness by age 45. The condition鈥檚 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 平特五不中鈥檚 Faculty of Medicine and the affiliated Jewish General Hospital (and formerly of King鈥檚 College), and Dr. Tim Spector of King鈥檚 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.
鈥淚 would presume male pattern baldness is caused by the same genetic variation in non-caucasians,鈥� said Richards, an assistant professor in genetic epidemiology, 鈥渂ut we haven鈥檛 studied those populations, so we can鈥檛 say for certain.鈥�
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.
鈥淲e鈥檝e only identified a cause,鈥� Richards said. 鈥淭reating 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.鈥�
鈥淓arly prediction before hair loss starts may lead to some interesting therapies that are more effective than treating late stage hair loss,鈥� added Spector, of King鈥檚 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.
鈥淭hat鈥檚 where the idea that baldness is inherited from the mother鈥檚 side of the family comes from,鈥� he explained. 鈥淗owever it鈥檚 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.鈥�
鈥淲hat鈥檚 startling is that one in seven men have both of those risk variants. That鈥檚 14 per cent of the total population!鈥�