Researchers at the Health Sciences department of the Universitat Jaume I (UJI) of Castellón, Spain, have identified the genes responsible for sun sensitivity and skin cancer vulnerability. The Skin Cancer Genetics and Human Pigmentation research group (Melanogén) has analysed the skin’s response to sun and the ability to get tan, and they have detected different genetic variants among the population of northern Europe. Results of this work appear in Photodermatology, Photoimmunology & Photomedicine.

The UJI study has analysed eight genetic variants related with pigmentation and sun sensitivity in saliva samples from 456 Spanish volunteers, 184 of which showed great vulnerability to sunburns, an indicative sign of cutaneous cellular damage.

Cutaneous pigmentation and the skin’s response to sun radiation are extremely relevant to determine susceptibility to skin cancer, and “a majority of studies have been conducted in northern Europe,” says researcher Conrado Martínez-Cadenas. In fact, the study conducted by the Melanogén group, “looks into the features of the population of a Mediterranean origin, who are characterised by a darker skin than people from an area with more intense radiation,” explains Dr. Martínez-Cadenas. Due to the increased intensity of ultraviolet radiation in the Mediterranean area, mainly during the summer months, evolution “has had an effect so that, for example, the proportion of people with the allele F374 in the SLC45A2 gene, responsible for darker skin, is more common in Spain than among northern European populations. It is worth noting that more than 96 percent of African people, who withstand an excess of sun radiation, have this genetic variant in their genome, which grants them protection against the negative effects of ultraviolet rays and skin cancer,” adds co-researcher Bárbara Hernando.

Four Main Genes

Melanogén researchers highlight that the four genes that play a significant role in cutaneous sensitivity to sun among the Spanish population are MC1R, IRF4, HERC2 and SLC45A2. “We know there is a genetic predisposition to suffering sunburns. The cutaneous response to the sun and the ability to get a tan is mainly related to a type of genetic variants in the MC1R gene – the R variants. These cause the gene to not work properly and for the body to synthesize pheomelanine instead of eumelanine, which results in people having clearer skin, blond or red hair and freckles,” says Dr. Martínez-Cadenas. However, this study indicates that “the synergic combination of several variants that determine sun sensitivity lead to added risk or a broader phenotype,” he adds

Researchers insist that prevention and early detection, as well as specific monitoring of the most susceptible population to developing skin cancer, are key for curing the disease.

Melanogén’s future research lines include studying the existence of an added risk of developing skin cancer depending on the pigmentary genotype and people’s phenotypic features. This would make it possible to advance in applying the genetic diagnosis as a tool to detect a person’s risk of developing a disease, to guide treatment decisions and assess the risk of developing a progression or recurrence of the disease. Furthermore, it would help specialists create personalised and accurate treatment depending on the risk of each individual patient.