Scientists have found a whole host of genes associated with human hair growth — including, for the very first time, a gene they believe contributes to hair going gray.
The study, published Tuesday in Nature Communications, also plucks out genes associated with monobrows, eyebrow and beard bushiness, hair color and shape, and balding.
“It was only possible because we analyzed a diverse melting pot of people, which hasn’t been done before on this scale,” study author Kaustubh Adhikari of University College London said in a statement. Adhikari and his colleagues sifted through the genetic data of over 6,300 men and women from across Latin America, covering a wide range of ethnic backgrounds. By taking note of their intrinsic hair traits and comparing them to their genomes, they were able to weed out which genes were often correlated to the same traits.
The gene IRF4, which was already known to influence hair color by helping to make and store melanin — the substance that gives our eyes, skin, and hair their distinct shades — is now pinned to graying hair, too. Hair goes gray with age when pigment cells stop producing melanin. IRF4 doesn’t cause gray hair, but its presence seems correlated with an earlier loss of hair color. That makes a lot of sense, since it was already associated with pale hair shades.