Rare Skin Disease Makes Citizens Melt Away in the Brazilian State of Goias

In the Brazilian state of Goias, situated in the center of the nation and home to the national capital of Brasilia, residents' expressions in the sunbaked hills of Araras are all but non-existent. Blood-red eyes peer through twisted expressions, across faces scorched and scarred by the sun. Home to a very rare, and very dangerous genetic skin disorder, Xeroderma pigmentosum, the residents of Araras have become "children of the night" as they evade the excruciating effects that sunlight has on their dermal layers.

Unlike unaffected individuals whose dermal layers and DNA of healthy skin cells are repaired after exposure to high-intensity/high-energy ultraviolet rays from the sun, those with Xeroderma pigmentosum (or XP as it is typically referred to) lack a functioning enzyme essential in the repair of the skin's DNA. Left unchecked, ultraviolet radiation can mutate the underlying dermal layers of the skin, leading to various forms of skin cancer.

Creating skin malignancies at a young age, the disease is extremely fatal without proper precautions, and limits age expectancy to on average 20 years, but only up to 40 years in rare cases. Metatastic melanoma and carcinoma, both malignant cancers in the basal layers of the skin, are primary causes of death in those with XP, however, most experience several forms of cancer throughout their lifetime.

Disfigured by the harmful rays of the sun, patients in Araras with XP experience severe skin pigmentation with increased exposure to the sun and typically lose facial features as excisions of cancerous skin become a necessary trial of life.

Resident Djalma Antonio Jardim admits that avoiding the sun has not been a successful tactic for him, as he has undergone in excess of 50 surgeries to remove cancerous skin tumors in his short 38-year-long lifetime. "The doctors I went to said I had a blood disorder" Antonio Jardim said. "Others said I had a skin problem, but none said I had a genetic disease. It was only in 2010 that my disease [Xeroderma pigmentosum] was properly diagnosed."

Largely seen in Japanese populations, this rare autosomal recessive genetic disorder is an even more extremely rare oddity in the middle of Brazil (where tropical farming is a necessary part of survival). Although the genetic disorder does not have a cure, as the genetic makeup of the individuals is the culprit for why their skin cannot regenerate or heal properly, researchers and genetic counselors now have a better understanding of the development of the disease in the population and can help mitigate growing numbers in generations to come.

A glaring example of the "Founder's Effect" in evolutionary models, the largest single group of patients with XP can easily be accounted for by the individuals' ancestors. Relatively secluded, the small community was established by few founding members, whose families have all interbred throughout the course of generations. As with any other autosomal recessive disorder, limited genetic diversity and interbreeding cause increased numbers of carriers for the disorders and increased rates of affliction. If families in the village continue to marry and reproduce within the small population, barring introduction of outside individuals, the disorder will likely spread to even more offspring until a majority of the community is afflicted with XP.

Scientists continue to search for viable treatments that will improve quality of life for individuals suffering with XP, however, as of now only suggest that patients avoid the sun at all costs. With a physical reminder of the genetic disorder their ancestors have passed on, this small Brazilian village continues to live nocturnally-avoiding the blistering light of the sun and hoping not to melt away in the heat of the day.