Skin cancer risk increased by hidden red hair gene.

New research suggests that a “silent” red hair gene could significantly increase individuals’ risk of skin cancer – and as many as one in four in the UK could be carriers. The research, led by a team at the Sanger Institute near Cambridge, confirmed that gene variants associated with red hair, pale skin and freckles are linked to a higher number of genetic mutations in skin cancers. The burden of mutations associated with these variants is comparable to an extra 21 years of sun exposure in people without this variant. Red-headed people make up 1-2% of the world’s population but about 6% of the UK population. They have two copies of a variant of the MC1R gene which affects the type of melanin pigment they produce, leading to red hair, freckles, pale skin and a strong tendency to burn in the sun. Their research also revealed, however, that even a single copy of a red hair-associated MC1R gene variant increases the number of mutations in melanoma skin cancer, the most serious form of skin cancer. Many non-red haired people carry these common variants without even realising that they are at greater risk as a result. The researchers analysed publically available data-sets of tumour DNA sequences collected from more than 400 people. They found an average of 42% more sun-associated mutations in tumours from people carrying the gene variant. Dr David Adams, joint lead researcher at the Wellcome Trust Sanger Institute, commented: “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. This is one of the first examples of a common genetic profile having a large impact on a cancer genome and could help better identify people at higher risk of developing skin cancer.” Vicki Kiesel, Genetic Director at GeneHealth UK (GHUK), added: “We all know we need to take care to limit our exposure to harmful UV rays, but while some are clearly at increased risk due to factors such as red hair, genetics or family history, many may not be aware that their risk is higher. Whilst treatments for cancer and means of detection are continually improving, I firmly believe that one of the best weapons we have in the fight against this disease is more accurate risk assessment. The more people understand their individual risk, the better equipped and motivated they are to avoid potential damage – but also, this means we are able to tailor screening programmes specifically for them, recommending more frequent tests for those who are at high risk, and reassuring those who do not need to be tested so often. This is clearly a more effective approach, and a more efficient use of resources.”