What are the risk factors for xeroderma pigmentosum?

Xeroderma pigmentosum (XP) is a rare genetic disorder that causes hypersensitivity to ultraviolet (UV) light, eye problems and neurological symptoms. It has no cure, but treatment can lower your risk of skin cancer and other complications.

XP is caused by mutations in at least nine specific genes that are involved in DNA repair. Normally, the damage to DNA which occurs in skin cells from exposure to UV light is repaired by nucleotide excision repair.

In people with xeroderma pigmentosum, this damage is not repaired. As more abnormalities form in DNA, cells malfunction and eventually become cancerous or die. Some of the risk factors for XP include:

• Having a family history of XP or being born to parents who are closely related (consanguineous).
• Living in regions where XP is more common, such as Japan, North Africa and the Middle East.
• Having fair skin, light eyes and blond or red hair.
• Spending a lot of time outdoors without sun protection.

People with XP usually start showing symptoms in early childhood. They may get blistering sunburns after only a few minutes in the sun, freckling in sun-exposed areas, dry skin, and changes in skin pigmentation.

The life expectancy of those with XP is about 30 years less than normal. The disease affects about 1 in 1 million people in the United States and Europe, but it is more common in other parts of the world.