Samples of DNA can give a high-probability estimate of someone's hair colour, a finding that will be a boon for forensic scientists, according to a new study published on Tuesday.
DNA taken from blood, sperm, saliva or skin cells can determine with more than 90-percent accuracy whether a person has red hair or black hair, and with an accuracy of more than 80 percent as to whether their hair is blond or brown, say its authors.
The technique, published in the European journal Human Genetics, can even differentiate between hair colours that are similar, such as red and reddish blond and blond and dark blond.
"That we are now making it possible to predict different hair colours from DNA represents a major breakthrough because, so far, only red hair colour, which is rare, could be estimated from DNA," said Manfred Kayser, a forensic molecular biology professor at Erasmus Medical Centre in Rotterdam in the Netherlands.
The research is based on 13 telltale signatures of DNA in 11 genes, which matched hair colours in hundreds of Europeans. It was based on hair on the head, and further research is needed to predict the colour of body hair.
The scientists believe that a standardised DNA test for predicting hair colour could emerge in the near future, adding powerfully to the forensic toolkit.