Melanoma is one of the most aggressive forms of skin cancer, says Dr. Geoffrey Young, Chief of Head & Neck Surgery at Miami Cancer Institute, who explains it is related to sun exposure. However, he adds, some families have genetic components, genetic changes that predispose them to melanoma. But the main risk factor is chronic sun exposure. Xeroderma pigmentosus is a rare genetic disorder that is caused by an inability or defect in repairing the DNA from damage from the UV light, according to Doctor Guilherme Rabinowits, Co-Leader of Head & Neck Oncology at Miami Cancer Institute. Probably one in 250.000 people develop that disease, he says.