Interactions Between Genetic Variants and Sun Behaviors May Influence Future Melanoma Risk
The combination of different patterns of sun exposure experienced by children and biomarkers of melanoma risk, such as the number of freckles or moles that develop as a result, may play a large role in future melanoma risk, a study investigating gene and environmental interactions has found. Children with the blue eye-color variant and genetic variants that cause red hair color are particularly susceptible to the formation of freckles and moles. Children with specific genetic variants may benefit from targeted preventive measures to counteract their inherent risk of melanoma. The study by Barón et al is published in Cancer Epidemiology, Biomarkers & Prevention.
Study Methodology
The researchers used DNA samples and information about the sun-behavioral patterns collected on 477 non-Hispanic or Hispanic white children ages 6 through 10, living in Colorado. The investigators followed the children from 2004 to 2008. The number of melanocytic nevi, facial freckling density levels, hair, eye, and constitutive skin color were recorded during annual skin exams. Ultraviolet (UV) light exposures and sun protection practices were assessed at the enrollment interview and at each annual telephone interview using a composite index that included shade seeking and sun-protective clothing, hat, and sunscreen use; the higher the composite score, the greater the protection behavior.
Waterside vacations were considered cumulatively, with numbers from birth to the year before each skin exam. The cumulative levels of chronic exposure as of each interview year were computed by summing scores on this variable over time starting in 2004. The cumulative total number of sunburns as of each interview year was obtained by summing the number of prior year sunburns across years starting with 2004.
Study Findings
The researchers found that the number of moles and freckle density increased among the children in each successive year. Additionally, total number of sunburns, waterside vacations, and chronic sun exposure increased each year. All of the measures of sun exposure contributed to increased freckle counts, and cumulative chronic ultraviolet exposure was a major driver of freckle development. The study also showed that children with certain combinations of the blue eye-color gene variant and genetic variants that cause red hair are especially susceptible to the formation of freckles and moles. Children who have particular red hair color gene variants display significantly more freckles as they experience more waterside vacations, the study demonstrated.
“We found that children who are homozygous for the major blue eye-color gene variant are particularly susceptible to formation of moles as they take more waterside vacations in early life,” said Neil F. Box, PhD, Assistant Professor in the Department of Dermatology at the University of Colorado in Denver, and corresponding author of the study, in a statement. “Those kids with certain combinations of the blue eye-color gene variant and genetic variants that cause red hair color were also more likely to have larger moles as they sustained more sunburns.”
While all children may benefit from sun protection, “a personalized sun protection strategy based on a child’s genetic makeup may be of additional value in counteracting melanoma risk,” concluded the researchers.
Dr. Box is the corresponding author for the Cancer Epidemiology, Biomarkers & Prevention article.
Funding for this study was provided by grants from the National Institutes of Health. The study authors reported no conflicts of interest.
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