While it has been long known that people with naturally red hair and pale freckled skin are more sensitive to UV exposure that causes damage to DNA and may lead to skin cancer, the latest study has attributed the increased risk of melanoma to a specific gene.
A joint project of scientists funded by Cancer Research UK and the Wellcome Trust has found that variants of the MC1R gene “in charge” of the ginger type individuals is also linked to a higher number of potentially dangerous DNA mutations.
From 26 to 40 percent of melanoma patients are the gene carriers, the study published in the Nature Communications journal on Tuesday, said, adding that the "work has significant implications for understanding the genesis of melanoma in these high-risk groups."
While it has previously been thought that the type of redheads' pale skin pigment allowed more ultraviolet to reach the DNA, researchers have now proved it is also the gene itself that may be potentially harmful.
"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," said David Adams, who co-led the study, as quoted by Reuters.
Having studied tumor samples from some 400 patients diagnosed with melanoma, the researchers have found 42 percent more mutations linked to sun exposure in tumors from people carrying the MC1R variant than among persons without the gene.
"This figure is comparable to the expected mutational burden associated with an additional 21 years of age," according to scientists.
But while around 1-2 percent of the world's population are redheads that might be aware of UV risks due to their complexion, more people are at higher risk caused by sun exposure without realizing it. People with ginger hair have two copies of the MC1R gene which alters melanin pigment production, but those with one copy may be fair-skinned but not have red hair.
"Unexpectedly, we also showed that people with only a single copy of the gene variant still have a much higher number of tumor mutations than the rest of the population," Adams said, with his study warning that people with highly photosensitive skin types, prone to sunburn and an inability to tan should take extra care when exposed to UV light.