People with red hair, light skin or freckles are more likely than others to develop the deadliest skin cancer -- malignant melanoma. A single gene greatly influences these traits. A new study now demonstrates that the same gene is especially likely to put individuals at risk for a particular type of melanoma that most often occurs in one's 40s or 50s -- regardless of whether the gene bearers are light-complexioned.
Researchers -- led by Boris Bastian, MD, of the UCSF Comprehensive Cancer Center and by Maria Teresa Landi, MD, PhD, from the National Cancer Institute -- report in the July 28 issue of Science that being born with variations in a gene called MC1R results in an especially high susceptibility to a genetically distinct form of melanoma. Like freckles, variants in the MC1R gene are relatively common among whites in comparison with the entire world population.
The Science study highlights again how important it is for the fair-skinned to avoid sunburn. The results also led the study authors to the suspicion that susceptibility to damaging mutations in a gene called BRAF may peak before adulthood in individuals born with MC1R variants.
The MC1R gene is the blueprint for a protein found on specialized skin cells called melanocytes. Variants cause melanocytes to make less of a protective pigment called melanin in response to UV exposure. However, MC1R variants may contribute to melanoma risk beyond their effects on pigmentation -- even dark-skinned or easily tanning persons with MC1R variants may be at increased risk.
(Note that in November 2007 the UCSF Comprehensive Cancer Center was renamed the UCSF Helen Diller Family Comprehensive Cancer Center.)
Read more at Jeffrey Norris, UCSF Science Cafe