Study identifies genes for graying hair

Mar 01, 2016, 2:04 PM EST
Source: Felix E. Guerrero/flickr
Source: Felix E. Guerrero/flickr
Researchers say they may have tracked down the first gene linked to gray hair, having conducted a study on the hair types and genomes of more than 6,000 people in five Latin American countries. The study also sheds light on genes related to developing unibrows. CNN reports:
[The researchers] looked in these populations because they represent a good mix of backgrounds: Europeans and their sometimes fair or curly hair, Native Americans and African-Americans and their characteristic dark and straight or kinky hair.
Many people already know they face increased risk of going gray at an early age, if they've seen older relatives do so. The current study adds more support to the notion that graying is genetic, said Kaustubh Adhikari, a research associate in cell and developmental biology at University College London. Adhikari is the lead author of the study, which was published on Tuesday in the journal Nature Communications.
The findings may have implications for forensics. Scientists can already identify genes and alleles—a variant form of gene—that affect whether a person has blue eyes or blond hair, says the paper’s senior author Dr. Andrés Ruiz-Linares, professor of human genetics at University College London. “Those are the ones that have been looked at the most, but we are trying to build a wider picture.” Being able to link specific genes to certain hair characteristics—like the ones found in the study—may one day help paint a fuller picture from a crime scene, for instance.
To study the unibrow in particular, they had to limit their analysis to men, says Ruiz-Linares. “We couldn’t tell how bushy the eyebrows of women were, because normally women sort of change that,” he says. But one gene in particular—called PAX3—was associated with the unibrow. “It basically means that alleles of these genes increase the chances that you have or you don’t have this feature,” he says.
The volunteers had highly mixed ancestry; this particular group was a mix of European (48 percent), Native American (46 percent), and African (6 percent) descent. Most past studies on hair genetics have taken place in Europe, which only represents a small portion of human diversity.