PHILADELPHIA--It's no surprise that people with red hair and fair skin sunburn easily and are prone to skin cancer. But even the tanned are at high risk of melanoma if they carry a copy of the recessive gene for red hair, researchers announced here on 5 October at the annual meeting of the American Society of Human Genetics. The researchers hope that a test for the gene could alert those at risk to be extra careful in the sun.
Most people with red hair and light skin know from experience that they burn easily. The reason they burn instead of tan is that they carry two copies of a version of a gene called MC1R that causes them to produce red pigments rather than brown in response to sunlight. People with just one "redheaded" version of the gene, in contrast, often have dark hair and medium or dark skin. But what is their risk of skin cancer?
To find out, molecular biologist Richard Sturm of the University of Queensland in Brisbane and his colleagues at the Queensland Institute of Medical Research collected DNA from 858 Australians with skin cancer. They focused on the gene MC1R. Sturm and his colleagues found that individuals with two copies of the MC1R version that leads to red hair and fair skin--redheads all--face a risk of melanoma four times greater than do Australians without the mutation. More surprisingly, people with just one copy have twice the risk, even though they aren't redheaded and can tan.
Identifying risky genes rather than risky skin tones, says clinical geneticist Peter Tishler of Harvard Medical School, might help target skin cancer prevention. Most people assess their risk based on self-perception, he says. "You need a more objective method of determining [a person's ideal] skin color," Tishler says, "because everyone in Australia is a sun buff."