For redheads, skin cancer may be in the genes

Ars hopes the model has a good dermatologist.

Bill Kuffrey

As a freckle-faced redhead, I’m constantly reminded to wear a hat and to slather myself with sunscreen. Even strangers on the street warn me to stay out of the sun. Unfortunately, I’m now faced with the fact that even these safeguards may not be enough to protect me from skin cancer. New research in Nature suggests redheads may be genetically predisposed to melanoma, even if they never see a ray of UV light.

Pigment production is controlled by a gene called MC1R, and is responsible for the veritable rainbow of human complexions. The relative abundance of two pigments (pheomelanin and eumelanin) determines hair and skin color. In dark-skinned individuals with dark hair, MC1R activity leads to production of large amounts of eumelanin, compared to relatively small amounts of pheomelanin. Redheads with fair skin have mutations that disrupt the MC1R pathway, producing more pheomelanin than eumelanin. We’ve long known that redheads are at a high risk of sun-induced skin cancer, but the researchers behind this study wondered whether something about pheomelanin itself may contribute to the high incidence of melanoma in those with fair skin, even in the absence of cancer-causing UV exposure.

To investigate this potential link, the researchers used strains of mice with pigment profiles that mimicked various human complexions. Like humans with dark skin, control mice with black coats had an intact MC1R gene and produced much more eumelanin than pheomelanin. A second strain of mice, with a mutated MC1R gene, had reddish coats and had a much higher pheomelanin to eumelanin ratio. The third strain of mice was albino, which produced no pigment at all.

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