If your hair turns grey overnight, don’t blame the stress of your job, relationship woes or a busy family life. It could just be your genes.
Researchers have found the a gene responsible for greying hair for the first time, confirming that going grey is not just influenced by environmental factors.
"We already know several genes involved in balding and hair colour but this is the first time a gene for greying has been identified in humans," said Dr Kaustubh Adhikari, lead author of the University of London-led study.
Over 6,000 people with varied ancestry across Latin America were studied to identify new genes associated with hair colour, greying and style - straight or curly.
The gene - IRF4 - is known to play a role in hair colour but this is the first time it has been associated with greying. It is involved in regulating production and storage of melanin, the pigment that determines hair, skin and eye colour.
Going grey is caused by an absence of melanin in hair, so the scientists now want to find out how the gene influences the process. Armed with that information it could be possible to slow or block the greying .
Another gene was found to influence hair curliness and the scientists found additional genes associated with beard thickness, hair shape, eyebrow thickness and the prevalence of monobrows.
“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,” said Dr Adhikari.
The team collected and analysed DNA samples from 6,630 volunteers recruited in Brazil, Colombia, Chile, Mexico and Peru. After an initial screen, a sample size of 6,357 was used – 45 per cent men and 55 per cent women.
This group included individuals of mixed European (48 per cent), Native American (46 per cent) and African (6 per cent) ancestry, giving a large variation in head hair appearance.
Both men and women were assessed for hair shape, colour, balding and greying, but only men were tested for beard, monobrow and eyebrow thickness.
The findings could help develop forensic DNA technologies that build visual profiles based on an person’s genetic makeup. The study was published in Nature Communications.
