By Theresa Tamkins

SUNDAY, Oct. 12 (Health.com) — About one in seven men has a combination of genes—one new and one first discovered in 2001—that increases his risk of male pattern baldness sevenfold, compared to men without the combination.

It’s a scientific finding that won’t grow hair on your head. But it could lead to better testing for a susceptibility to male pattern baldness, a problem that vexes about 40 million men in the United States.

Two independent research teams made the discovery, and both teams published the information Sunday in the journal Nature Genetics.

They found that certain variations in a chunk of DNA located on chromosome 20 appear to increase the risk of male pattern baldness. However, this DNA section doesn’t have a clear link to hair or skin—so they’re not sure why it affects hair loss.

The researchers also confirmed that a second gene region, first discovered in 2001, is linked to male pattern baldness. That gene, found on the X chromosome, affects the androgen receptor, which binds to male hormones.

Overall, 14% of the (mostly white) men who were tested had variations in both gene regions, and those men were seven times as likely to have male pattern baldness as men who didn’t have both of the so-called risk variants, according to a team led by Tim Spector and other researchers at King’s College London.

“This is a very exciting and convincing finding,” says Justine Ellis, PhD, a research fellow at the University of Melbourne, who was not involved in the study. “This looks to be the next most important genetic variant—after the androgen receptor variant—that predisposes to hair loss in men.”

The finding could help explain female hair loss too, she says. Women with the chromosome-20 variations were at greater risk of hair loss, but the link was not as strong as it was in men.

“Female pattern hair loss has many similarities to male baldness, but it is unclear whether the same genes act in females as males,” Ellis says. “This study suggests that there is at least an overlap.”

Next: Should you be tested for baldness genes?