The color of our hair depends on more than 100 different genes. A team from King's College London identified them during a forensic medicine study. Scientists will use the discovery to determine a person's appearance from DNA alone. In this way it will be easier to identify a suspect of murder or to determine the appearance of an unrecognizable victim.
There are already a number of genetic tests that determine the color of the hair. These tests, however, are very reliable in identifying black hair, much less in identifying those brown or blonde. The London study has made it possible to develop a test that is 10-20% more accurate than the current ones. In case the owner of the DNA tracks has red or black hair, the reliability rate is about 90%.
The color of the hair depends for 97% on hereditary genetic factors. Nevertheless, until today only 13 genes related to this physical characteristic were known. The study of Dr. Tim Spector has identified another 124, thanks to the DNA of almost 300,000 people. Some genes are linked to the regulation of melanin, others determine biological mechanisms.
The new genes identified explain 35% of red hair, 25% of blonde hair and 26% of black hair. It is therefore likely that there are hundreds of other genes involved and still unknown. For the moment the mechanisms underlying these factors are too subtle to be identified. Furthermore, the role of the identified genes is also unclear sometimes.
Some children are born blond and change hair color while growing. The phenomenon certainly has a genetic basis, but scientists have no idea what this is. Even among the new genes, one is missing that can explain the reason for this change.