Redhead gene may boost skin cancer risk

‘Exercise extra care when going out in Sun’

Mexican pediatric oncologist Sergio Gallegos, disguised as a traditional Mexican wrestler, poses with a patient at a hospital in Guadalajara, Mexico on July 12.

Gallegos believes the mood of his patients is very important for the success of cancer treatment, so he disguises as different characters. (AFP)

PARIS, July 13, (Agencies): A gene variant carried by people with red hair, pale skin and freckles may boost skin cancer risk even without exposure to the Sun’s rays, researchers said Tuesday.

The risk, rather surprisingly, is also higher for people who possess the genetic DNA signature but not the telltale physical traits, reported the international team.

The findings, published in the journal Nature Communications, are based on a genetic analysis of skin cancer tumours from more than 400 people.

It revealed that tumours from people with a redhead variant of the MC1R gene had 42 percent more mutations -the equivalent of 21 years of additional Sun exposure in people without it.

Cell

Though most gene mutations are innocuous, the more that occur, the more likely a normal human cell will be to change into a cancer cell.

The findings suggested that people with an MC1R variant are more susceptible to mutagenic processes, such as UV exposure for example, that can trigger skin cancer, known as melanoma.

“This work is significant because its conclusions apply to a high proportion of the population, those people that carry at least one copy with a genetic variant in MC1R,” study co-author David Adams of the Wellcome Trust Sanger Institute told AFP.

In some countries, such as England and Ireland, this could be as much as a third of the population -- though only about one or two percent of all people have red hair.

Many of those at risk will not even know that they carry the variant, said the researchers.

Redheads receive one copy of the gene variant from each of their parents. But people who get a copy from their father or mother alone, will probably not have ginger hair -- and may remain oblivious of their particular genetic makeup.

It has long been known that redheads burn easier in the Sun and are more suspectible to the mutagenic effects of UV light -- thus also at higher risk of skin cancer.

But the new study suggests there are more ways, “possibly UV-independent” in which MC1R variants can increase the risk of melanoma, said Adams.

It also revealed for the first time, the risk to non-redhead carriers of the gene variant.

“These people should exercise extra care when going out in the Sun as they might be highly susceptible to UV radiation and other mutagenic mechanisms, something that many people carrying MC1R genetic variants don’t realise,” said Adams.

Carrying

People with red-haired relatives have a higher chance of carrying an MC1R variant, and should take extra care, said the team.

It was not clear whether the mutations mean that melanoma in redheads is more or less severe.

Exposure to ultraviolet light from either the sun or sunbeds causes damage to DNA and scientists think the type of skin pigment linked to redheads may allow more UV to reach the DNA.

In this latest study, the researchers found that while this may be one factor in the damage, there are also others linked to the crucial MC1R gene.

The research showed the MC1R gene variation not only increased the number of spontaneous mutations caused by sunlight, but also raised the level of other mutations in the tumours.

This suggests, the researchers said, that there are biological processes in the way cancer develops in people with MC1R variation that are not only related to ultraviolet light.

“This ... explains why red-haired people have to be so careful about covering up in strong sun,” said Julie Sharp of the charity Cancer Research UK, which cofunded the research.

“It also underlines that it isn’t just people with red hair who need to protect themselves from too much sun.”