A gene responsible for gray hair has been identified by researchers at University College London. The researchers hope that it will be possible to create drugs to turn off the gene.
Gray hair is caused due to lack of melanin, a pigment which is responsible for color in hair, eyes and skin. Graying of hair is viewed as an alarming sign of aging. A gene called IRF4 played a crucial role in hair color. Now the scientists are able to link the gene for graying of hair.
"We already know several genes involved in balding and hair color, but this is the first time a gene for graying has been identified in humans, as well as other genes influencing hair shape and density," said lead author, Dr Kaustubh Adhikari, UCL Cell & Developmental Biology.
The researchers analyzed DNA samples from more than 6,600 volunteers to find out the cause of graying hair. The study participants were from Brazil, Colombia, Chile, Mexico, and Peru. The study group included individuals of mixed European (48%), Native American (46%) and African (6%) ancestry, giving a large variation in head hair appearance.
Visual traits for each individual were compared to whole genome analysis results to identify the genes that are driving differences in appearance.
The gene identified for hair color IRF4, is known to play a role in graying of hair. The findings suggest that changing hair or eye color could be possible without using dyes. The findings could pave the way for drugs that can change the expression of certain genes to alter appearance, or preventing gray hair.
Professor Andres Ruiz-Linares, UCL Biosciences, who led the study, said, "We have found the first genetic association to hair graying, which could provide a good model to understand aspects of the biology of human aging. Understanding the mechanism of the IRF4 graying association could also be relevant for developing ways to delay hair graying."
Several other genes that play an important role in physical appearance were also identified. A gene EDAR was found to be linked to the ability to grow a full, bushy beard. The eyebrow thickness was found to be determined by FOXL2. A variant of PAX3 made a monobrow and PRSS53 was found to influence hair curliness.
"An enduring fascination of human evolution has been our peculiarly luxuriant scalp hair, and finding a new variation in the PRSS53 gene provides an important insight into the genetic controls underpinning scalp hair shape and texture," explained Professor Desmond Tobin, University of Bradford who investigated PRSS53 at the Centre for Skin Sciences as part of the study.
"The PRSS53 enzyme functions in the part of the hair follicle that shapes the growing hair fiber, and this new genetic variation, associated with straight hair in East Asians and Native Americans, supports the view that hair shape is a recent selection of the human family."
The findings of the study could help develop forensic DNA technologies that build visual profiles based on a person's genetic makeup. A person's genetic make-up could reveal the hair color, texture, and even eye color.
The research was published in the journal Nature Communications.