Researchers led by the Yale School of Public Health have for the first time identified a gene that appears to be associated with tanning dependence.
An exome-wide association study was conducted among 292 people, 79 of whom exhibited symptoms of tanning dependence. Researchers examined approximately 319,000 rare and common genetic variants primarily within the protein coding regions and found that variation in one gene—known as patched domain containing 2 (PTCHD2)—was significantly associated with tanning dependence.
While the precise function of PTCHD2 is unknown, its product is expressed mainly in the brain. People with one or more variants in PTCHD2 were about two thirds less likely to be classified as tanning dependent. Analogous to substance dependence, tanning dependence is defined by specific behaviors and symptoms, such as continued and frequent tanning despite adverse consequences.
“This is very exciting as this is the first time that a genetic association with tanning dependence has been reported,” said Brenda Cartmel, a senior research scientist at Yale and the study’s lead author. “If the finding is replicated, it will help us understand more about the biology of tanning dependence and may help in the development of interventions to help people reduce indoor tanning and sunbathing which expose them to ultraviolet light, a known human carcinogen.”
Cartmel noted that the finding is limited by a relatively small sample size and it needs to be replicated in a larger study. She added that publication of the findings may stimulate others groups to collect data on tanning dependence to facilitate replication, and that the Yale research team welcomes collaboration on such a project with other groups in the future.
The findings are published online in the journal Experimental Dermatology.
The research is part of a larger skin cancer research program being conducted by Cartmel and YSPH colleagues Leah M. Ferrucci, an associate research scientist, and Susan T. Mayne, the C.-E. A. Winslow Professor of Epidemiology, focusing on skin cancer and its prevention in young people.
The Surgeon General recently released a “Call to Action to Prevent Skin Cancer,” which highlights the dangers of both indoor tanning and outdoor exposure to ultraviolet light and the cost of skin cancer to both individuals and the nation, and calls for more efforts to be made, including more research, to prevent skin cancer.
The eight-member research team also included Yale scientists Allen Bale, Andrew DeWan, Joel Gelernter, David Leffell, Ferrucci and Mayne, and Jerod Stapleton of the Rutgers Cancer Institute of New Jersey.