Researchers searching for the genetic roots of hair loss say they've found more than 280 different genes are involved.
And they've come up with a formula that can predict a man's risk of losing his hair, although it's too soon to say there could be a blood test to forecast whether and when a man would start losing his hair.
Douglas Robertson, University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology / PLoS Genetics
It turns out that hair loss is very complicated genetically, the British team reports in the Public Library of Science journal PLoS Genetics.
"In this large genome-wide association study study of male pattern baldness, we identified 287 independent genetic signals that were linked to differences in the trait," Riccardo Marioni and colleagues at the University of Edinburgh wrote.
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"The results of this study might help identify those at greatest risk of hair loss, and also potential genetic targets for intervention."
The team studied the DNA from more than 52,000 mostly middle-aged men taking part in a gigantic British genetic experiment called BioBank.
“Male pattern baldness affects around 80 percent of men by the age of 80 years.”
"We identified hundreds of new genetic signals," said Saskia Hagenaars, a student who worked on the study.
Although hair loss runs strongly in families, men cannot always look at their fathers and predict their own fates, hair-wise. Some can blame their mothers, the researchers found.
The trawl though all of the mens' genes found 40 linked with baldness on the X chromosome. The rest were scattered across the genome.
"It was interesting to find that many of the genetic signals for male pattern baldness came from the X chromosome, which men inherit from their mothers," Hagenaars said in a statement.
Of the men in the study, 16,700 had no hair loss. Another 12,000 had slight hair loss; 14,000 had moderate hair loss and 9,800 had severe hair loss.
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The researchers linked each man's genetic pattern with the degree of hair loss.
Those with fewer-than-average hair loss genes were predictably less likely to go bald. Only 14 percent in this group were bald and 39 percent hadn't lost any hair at all.
And 58 percent of those with the top 10 percent count of baldness genes also had some hair loss.
That makes the genetic pattern only somewhat predictive.
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However, it's possible to predict whether a man will lose hair with pretty good certainty. Most are fated to at least have their hair thin out. "Male pattern baldness affects around 80 percent of men by the age of 80 years," the researchers wrote.
"We are still a long way from making an accurate prediction for an individual's hair loss pattern," Marioni said in a statement.
"However, these results take us one step closer. The findings pave the way for an improved understanding of the genetic causes of hair loss."...Read more