Scientists have discovered eight genes linked to red hair, helping solve the mystery of how redheads inherit their flaming locks. The study — which also sheds light on blondes and brunettes — is the largest genetic study of hair color to date. Red hair was thought to be controlled by a single gene called MC1R. The new research sheds light on other genes involved.
Previous studies have shown that redheads inherit two versions of the MC1R gene that lead to red hair — one from their mother and one from their father. While almost everyone with red hair has two copies of the redhead version of MC1R, not everyone who wears two redhead versions is a redhead. Scientists knew there were other genes involved, but these have mostly remained a mystery until now.
Now, researchers from the University of Edinburgh have looked at DNA from nearly 350,000 people who took part in the study. The study focused on people of European descent because they have more variation in hair color. By comparing redheads to people with brown or black hair, they identified eight previously unknown genetic differences associated with red hair.
The team also looked at the functions of the genes they identified and found that some of them work by determining when MC1R is turned on or off.
In addition to the redhead genes, the researchers uncovered differences in nearly 200 genes associated with blondes and brunettes. Scientists say there is a color gradient from black, through dark brown to light brown and blond, which is caused by an increasing number of genetic differences in these 200 genes.
The researchers were surprised that many of these 200 genetic differences were related to hair texture rather than pigmentation. Others are involved in determining how hair grows – curly or straight, for example.
