IT IS one of men's biggest fears as they age – but a genetic discovery means baldness could be prevented in generations to come.
As their plugholes become clogged and combs grow increasingly redundant, many turn to lotions, potions and surgical remedies to hold back hair loss.
But now researchers have discovered genetic links that explain how baldness can be passed from
father to son.
The findings could help lead to treatments to stop men losing their hair, and prevent the resulting mental anguish.
The research, published in the journal Nature Genetics, focuses on detailed studies of men's genetic make-up.
Until now, the only known genetic link with male baldness was on the female chromosome, meaning it could be passed down to men from their mother's father.
Estimates suggest more than 80 per cent of cases of male- pattern baldness – which causes the distinctive M-shaped hairline – are inherited.
Dr Tim Spector, from King's College London, and colleagues in Canada, Iceland, Switzerland and the Netherlands, studied 1,125 Caucasian men, and found inherited baldness was closely linked with genetic variations in two regions of chromosome 20.
The chromosome – one of the bundles of DNA in every cell that contain genes – can be inherited from the mother or the father, meaning baldness is no longer linked solely to the female line of the family.
Researcher Dr Brent Richards, from McGill University in Montreal, Canada, said: "It's long been recognised 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 (female] chromosome, your risk of going bald increases seven-fold."
The findings were backed by another team, from the University of Bonn in Germany, whose study of 300 men with serious hair loss found a link with the same two genetic variations.
Around 14 per cent of men are believed to carry these two chromosome-20 variants.
It is unclear how the genes may cause baldness, but experts suspect one variant might influence male hormone activity.
There is now hope the findings could help the search for hair-loss treatments.
Dr Spector said: "Early prediction before hair loss starts may lead to some interesting therapies that are more effective than treating late-stage hair loss."
Dr Richards said so far they had only identified a cause of hair loss.
"Treating male-pattern baldness will require more research," he said. "But, of course, the first step in finding a way to treat most conditions is to identify the cause."
The full article contains 444 words and appears in The Scotsman newspaper.
