The MC1R gene variant can boost the risk of skin cancer by the equivalent of 21 extra years of sun exposure, say scientists.
Red-haired people such as Prince Harry, and DJ and broadcaster Chris Evans have two copies of the variant, which causes a strong tendency to burn in the sun.
But even a single copy of the variant, found in many people without red hair and freckles, increases the number of gene mutations associated with malignant melanoma, the deadliest form of skin cancer, research shows.
The MC1R variant affects the type of melanin skin pigment they produce, leaving red-haired people especially vulnerable to damage from the sun’s ultraviolet (UV) rays.
Lead researcher Dr David Adams, from the Wellcome Trust Sanger Institute in Hinxton, Cambridgeshire, said: “It has been known for a while that a person with red hair has an increased likelihood of developing skin cancer but this is the first time that the gene has been proven to be associated with skin cancers with more mutations.
“Unexpectedly, we also showed that people with only a single copy of the gene variant still have a much higher number of tumour mutations than the rest of the population.”