- More than 200 new genetic markers linked to baldness in men is identified.
- Single-nucleotide polymorphisms, or SNPs, are linked with severe hair loss.
- Forty of the genetic variations were located on the X chromosome, which men inherit from their mothers.
Male pattern baldness have been linked with genetic markers that cause them. Now, more than 200 new markers have been identified.
The researchers in the new study were also able to use their set of genetic markers to predict men's chances of severe hair loss, although the scientists noted that their results apply more to large populations of people than to any given individual.
‘One of the genes on the X chromosome, the gene for the androgen receptor, which binds to the hormone testosterone was strongly linked with severe hair loss.’
"We are still a long way from making an accurate prediction for an individual's hair-loss pattern. However, these results take us one step closer," said study co-author Riccardo Marioni, of the University of Edinburgh's Centre for Genomic and Experimental Medicine.
"The findings pave the way for an improved understanding of the genetic causes of hair loss," Marioni said.
In the study, the researchers analyzed information from more than 52,000 men ages 40 to 69 years in the United Kingdom. Of these men, about 32 percent said they had no hair loss, 23 percent said they had slight hair loss, 27 percent said they had moderate hair loss and 18 percent said they had severe hair loss.
The researchers then analyzed participants' genomes, looking for genetic variations, known as single-nucleotide polymorphisms, or SNPs, that were linked with severe hair loss. That search revealed 287 genetic variations, located on more than 100 genes, that were linked with severe hair loss.
Many of the genetic variations were located on or near genes that have previously been linked with hair growth, hair graying or the biological structures involved in making hair, the researchers said.
Forty of the genetic variations were located on the X chromosome, which men inherit from their mothers, the researchers said. One of the genes on the X chromosome — the gene for the androgen receptor, which binds to the hormone testosterone — was strongly linked with severe hair loss. Previous studies have also pinpointed this gene as tied to male pattern baldness.
The researchers then created a formula, which resulted in a genetic "risk score," to try to predict the chances of severe hair loss in the men.
Among those men with a below-average score, 39 percent had no hair loss and 14 percent had severe hair loss. In contrast, among those with a high score that put them in the top 10 percent of those in the study, 58 percent had moderate-to-severe hair loss.
The researchers noted that in the study, they did not collect information on the age at which the men started losing their hair. The scientists said they would expect to see even stronger genetic associations with hair loss if they were able to include information about which men experienced early onset hair loss.
As more information from these participants becomes available, the researchers may be able to further refine their predictions, they said.
- Saskia P. Hagenaars et al., Genetic prediction of male pattern baldness, Plos Genetics (2017)