Scientists have discovered that 1 in 7 men have a genetic risk for baldness. Researchers at Canada's McGill University and King's College London along with scientists at drug company GlaxoSmithKline have solved the mystery of male pattern baldness but say treating it will require more research.
The scientists have identified two genetic variants in Caucasians that together produce an astonishing sevenfold increase in the risk for male baldness.
Male pattern baldness is the most common form of baldness and usually involves hair loss above the temples and at the crown of the head - it affects about one-third of men by age 45.
The researchers say the condition's social and economic impact is considerable - in the United States alone in 2007 the cost for hair transplantation alone exceeded $115 million, while global revenues for medical therapy for male-pattern baldness recently surpassed $405 million. Estimates suggest more than 80 per cent of cases are hereditary.
The study, conducted by Dr. Vincent Mooser of GlaxoSmithKline, Dr. Brent Richards of McGill University and Dr. Tim Spector of King's College, along with colleagues in Iceland, Switzerland and the Netherlands, conducted a genome-wide search in 1,125 Caucasian men with male pattern baldness.
The search revealed two previously unknown genetic variants on chromosome 20 that substantially increased the risk of male pattern baldness which was then confirmed in an additional 1,650 Caucasian men.
Dr. Richards suggests that male pattern baldness could be caused by the same genetic variation in non-Caucasians.
The researchers say though they consider their discovery to be a scientific breakthrough, it does not mean a treatment or cure for male pattern baldness is imminent, but they say the ability to predict hair loss early may lead to some interesting therapies that are more effective than treating late stage hair loss.
The researchers say it was already known that a genetic variant on the X chromosome was linked to male pattern baldness, which is where the idea that baldness is inherited from the mother's side of the family comes from - but it was also suspected that there were several genes causing male pattern baldness - the newly discovered gene on chromosome 20 can be inherited from both the mother and father.
Having both the risk variants discovered on chromosome 20 and the unrelated known variant on the X chromosome, increases the risk of becoming bald sevenfold which equates to 14% of the total population.
Their results are published in the journal Nature Genetics.