Researchers have found evidence that gene variants associated with red hair, pale skin and freckles are linked to a higher number of genetic mutations in skin cancers, according to a study published Tuesday in the journal Nature Communications.
People with red hair make up between one and two percent of the world's 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.
The study is led by researchers at the Wellcome Trust Sanger Institute and University of Leeds, who analyzed publicly available data sets of tumor DNA sequences collected from more than 400 people. They found an average of 42 percent more sun-associated mutations in tumors from people carrying the MC1R gene variant.
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 one of the study's authors Dr. David Adams.
Even a single copy of a red hair-associated MC1R gene variant can increase the number of mutations in melanoma skin cancer, which is the most serious form of skin cancer, according to the study. Many non red-haired people carry these common variants and the study shows that everyone needs to be careful about sun exposure.
"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. 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," said Adams.