The genes associated with different hair colours are identified in a paper published online this week in Nature Genetics. These findings highlight the genetic roots of human hair pigmentation, and could help inform population genetics and forensic science studies by allowing for predictions of hair colour, to a certain degree of accuracy, from DNA evidence alone.
Natural pigmentation in humans - like skin or hair colouration - is brought about by two types of melanin. Studies on twins show that, for hair, melanin production and distribution have an overwhelmingly heritable nature, with inherited factors accounting for almost 97% of colour variation. Pirro Hysi, Manfred Kayser, and colleagues analyse genetic data from almost 300,000 European individuals with black, blonde, dark brown, light brown or red hair. They identify over 100 new candidate genes that may help determine hair colour, including some that act on pigmentation and creation of the natural pigment melanin.
The authors also attempted to predict a person’s hair colour on the basis of these associated genes. They find that they can anticipate black and red hair with high accuracy, but predicting blonde and brown hair is more challenging. They also report a higher prevalence of lighter hair colours among women, suggesting an association between sex and hair colour.