Gene variants associated with red hair, pale skin and freckles appear to be linked to a greater number of genetic mutations in melanomas, researchers reported in a study published online in Nature Communications (July 12, 2016).
The overall goal of the study was to determine the likelihood of increased mutations of melanomas in patients with red hair. During the study, the researchers analyzed publically available data-sets of tumour DNA sequences collected from more than 400 people.
“This study [looked] at how the inherited Melanocortin 1 receptor (MC1R) gene affects the number of spontaneous mutations in skin cancers and has significant implications for understanding how skin cancers form,” said Prof. Tim Bishop, joint lead author and director at the University of Leeds Institute of Cancer & Patholody in Leeds, U.K.
“It has only been possible due to the large-scale data available. The tumours were sequenced in the U.S. from patients all over the world and the data was made freely accessible to all researchers,” added Prof. Bishop, who was quoted in a press release.
MC1R gene variant, UV light
Overall, the findings showed that even a single copy of a red hair-associated Melanocortin 1 receptor (MC1R) gene variant increased the number of mutations in melanoma skin cancer.
Interestingly, the researchers also indicated that they found an average of 42% more sun-associated mutations in tumours from people carrying the MC1R gene variant.
The study also revealed that the MC1R gene variation not only increased the number of spontaneous mutations caused by ultraviolet light, but also raised the level of other mutations in the tumours. This suggests that biological processes exist in cancer development in people with MC1R gene variation that are not solely related to ultraviolet light, the researchers reported.
“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 Dr. David Adams, senior group leader at the Wellcome Trust Sanger Institute in Hinxton, Cambridge, U.K.
“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,” added Dr. Adams.