Whether you call them gingers, the devil’s spawn or just-plain sexy, be sure to call redheads out of the sun because along with their fiery tresses comes a powerful propensity to develop melanoma, a particularly deadly form of skin cancer.

And now, scientists are beginning to uncover why redheads — and probably the non-gingers who carry a genetic variant common to redheads — may be so vulnerable: For those who carry an allele, or gene variant, associated with red hair and freckles, cancer-causing genetic mutations occur at a rate 42 percent greater than they do for people who don’t carry that gene variant.

As a result, the average carrier of at least one problematic variant of the melanocortin 1 receptor, or MC1R, gene tends to develop cancer-promoting mutations at roughly the same rate as a person 21 years her senior.

And that’s despite the known tendency of such people to avoid spending days in the sun, a factor known to initiate cellular changes leading to skin cancer.

Redheads comprise an estimated 1 percent to 2 percent of the world’s population, and as much as 10 percent to 13 percent of the population in Scotland and Ireland, respectively. But they make up 16 percent of the world’s population of melanoma patients.

At the same time, 26 percent to 40 percent of melanoma patients are carriers of at least one R allele of the MC1R gene, which, because it is recessive, will not always result in redheadedness and freckling. So, physicians treating people with red hair or a tendency to freckle, or whose parents did, have long been aware that something was up.

A study was published this week in the journal Nature Communications done by an international team led by cancer geneticists from the United Kingdom who scoured the “germline” genes of 273 melanoma patients.