Do You Tan or Burn? What Genes Say About Your Skin in the Sun

With summer fast approaching, many turn their thoughts to swimsuit bods and summer tans. Now, a new genetic study might help explain why some of us burn while others tan.

The answer could help predict who gets skin cancer, because severe sunburns, particularly in childhood, strongly intensify skin cancer risk.

Mario Falchi of King's College London led an international team that analyzed the genomes of more than 170,000 subjects who self-reported their tendencies to burn or bronze.

"Using such a big sample size, we were able to identify new genes involved in sunburn, because these, obviously, are genes that are relevant also for skin cancer and melanoma."

The international team's Nature Communications paper identifies 10 new pigmentation genes and links skin cancer to a gene that lowers skin's tanning ability.

Skin cancer is by far the most commonly diagnosed cancer in the United States; in 2009, new skin cancer cases outstripped breast, prostate, lung and colon cancer diagnoses combined.

Falchi recommended taking appropriate precautions, but added that avoiding the sun entirely is not the best approach.

"Sun exposure is a balance: You cannot expose too much, because you can get skin cancer; but you shouldn't avoid the sun, because then you have a vitamin D deficiency and other serious problems."

This story is from the Arizona Science Desk, a collaborative of the state's public radio stations, including NPR 89.1. Read more from the Arizona Science Desk.