Sometimes mocked, sometimes admired for their fiery hair, redheads hold a secret that geneticists have, until now, struggled to find the answer to. But that’s finally over, as a study published in December 2018 in the Nature Communications journal reveals.
There are eight. Eight genes that are responsible for the redness of some people’s hair and their freckles. Whereas previously, there was only one gene - MC1R - that was suspected to cause reddish hair, a team from the University of Edinburgh, Scotland, has revealed that eight other genes are also involved.
A major study
During the course of their study, geneticists analysed genetic data taken from nearly 350,000 people. This data was collected during the UK Biobank study, a vast program that started back in 2006 to gain a better understanding of the role of genetic predispositions in the appearance of certain pathologies.
By comparing the genes of redheads with those collected from men and women with brown or chestnut-coloured hair, researchers were able to identify eight sequences that were specific to redheads. They found that some of these eight genes work by controlling when the MC1R gene, the gene supposedly responsible for giving redheads their flamboyant, fiery hair, is turned on or off.
‘We are very pleased that this work has unravelled most of the genetic variation contributing to differences in hair colour among people,’ said Albert Tenesa, one of the study’s researchers from the Roslin Institute at the University of Edinburgh.
Blonds and brunettes were also studied
However, the study didn’t just end when the geneticists identified these eight new genes involved in red hair, but they also went on to discover around 200 other genes, variants of which sometimes lead to blond and brown hair.
Of these 200 genetic differences, many did not involve variation in pigmentation, but rather in hair texture instead. This was an astonishing discovery for the researchers who also managed to identify the genes responsible for curls that give some people’s hair volume and bounce and those responsible for straight hair as well.
‘It has provided fascinating insights into what makes us such distinct individuals,’ concludes Melanie Welham, Executive Chairman of the Biotechnology and Biology Sciences Research Council (BBSRC), one of the seven research councils in the UK.