Scientists have uncovered the genes at the center of some hairy business, finding the genetic reason why some people develop unibrows or grey hair.
In a paper published today in the Nature Communications Journal, researchers revealed they have found genes associated with multiple hair traits, including grey hair, unibrows and even beard thickness.
The researchers from the United Kingdom, Peru, Spain, Chile, Argentina, Mexico, Colombia and Brazil studied 6,630 people in Latin America to see how different genes are related to hair color, greying hair, hair density and if hair is straight or curly.
They found that there is an actual gene associated with grey hair called IRF4. The gene was known to be related to hair color, but not to how hair turns grey. It affects the regulation of melanin, the pigment that affects hair, eye and skin color.
"We already know several genes involved in balding and hair color but this is the first time a gene for greying has been identified in humans, as well as other genes influencing hair shape and density," the lead author, Dr. Kaustubh Adhikari of the University of College London Cell & Developmental Biology, said in a statement today.
Understanding the gene's effect on hair color could lead to developing a treatment that stops or delays grey hair from developing on a genetic level, the study authors said.
"It was only possible because we analysed a diverse melting pot of people, which hasn't been done before on this scale," Professor Andres Ruiz-Linares of the University College of London Biosciences, who led the study, said in a statement. "These findings have potential forensic and cosmetic applications as we increase our knowledge on how genes influence the way we look."
By working with a large and diverse sample size, the team was even able to find a gene called PAX3, linked to the prevalence of unibrows, or "monobrows." Finding these genes supports evidence that hair features evolved through natural selection, the study authors said.
"The genes we have identified are unlikely to work in isolation to cause greying or straight hair, or thick eyebrows, but have a role to play along with many other factors yet to be identified," Adhikari said.
Identifying the genes could lead to important insight in how we age and help researchers understand how people appeared in past civilizations, the authors said.