The white horse has had a huge impact on human culture across the world. An international team led by researchers at Canterbury University has now identified the mutation causing this spectacular trait and show that all white horses carry the same mutation that can be traced back to a common ancestor that lived thousands of years ago. The study is interesting for medical research since this mutation also increases the risk for melanoma.The great majority of white horses carry a dominant mutation that results in rapid greying with age. A "Grey" horse is born coloured (black, brown or chestnut) but the greying process starts very early in life -- during its first year. These horses are normally completely white by six to eight years of age but the skin remains pigmented. Thus, the process resembles greying in humans but the process is ultrafast in these horses. The research shows that all grey horses carry exactly the same mutation which must have been inherited from a common ancestor.
