Your genetic heritage influences your risk of skin cancer.
About 5 to 10 percent of all cases of melanoma are inherited. Parents who have the genetic mutation that causes hereditary melanoma have a 50/50 chance of passing on their high susceptibility to melanoma to each of their children.
Researchers have identified the gene that causes about 40 percent of all cases of hereditary melanoma. Mutations in this gene, which is called p16, result in unregulated growth of the melanocytes (melanoma is a cancer of the melanocytes, which are the pigment-forming cells in the skin). People with a mutation in this gene have at least a 50 percent risk of developing melanoma at some time in their lives.
People who inherit the gene for a condition called basal cell nevus syndrome or Gorlin's syndrome also have an increased risk of skin cancer. Basal cell nevus syndrome is a condition that affects the skin, nervous system, eyes, bones, and certain glands. People who have it may develop many basal cell carcinomas as young adults, far earlier in life than the typical age for the development of this cancer.
Another hereditary medical condition that increases skin cancer risk is xeroderma pigmentosum. People with this disease do not have the normal ability to repair damage caused by ultraviolet light. As a result, they are extremely sensitive to sunlight, so much so that some families who have children with xeroderma pigmentosum live on reversed day/night cycles, sleeping during the daylight hours and going outdoors only when it is dark. Xeroderma pigmentosum increases the risk of skin cancer by a factor of 1000, and most patients with this condition develop skin cancer by the time they are eight years old.
Less dramatically, simply inheriting the genes for light-colored skin from your parents increases your risk of developing skin cancer. The lighter your skin, the more it absorbs ultraviolet light, and the higher your risk of skin cancer. Light-skinned people need to be especially careful to protect themselves against sunlight. They should also learn how to examine their own skin for signs of skin cancer and have a doctor examine their skin if they notice any suspicious changes.