Ultraviolet Light – From Science to Protection for XP

Xeroderma Pigmentosum (XP) is a genetic disorder whereby a person’s DNA lacks the ability to repair itself when damaged by ultraviolet light (UV) or other mutagens. Of its many complex functions, DNA repair is predominantly used by skin cells to repair sun damage. When DNA is damaged and left unrepaired, mutations in the genetic code are replicated after cell division. As a result, newly formed cells are mutated at creation and do not function as they should. The damage that is left unrepaired in XP cells is irreversible. Some of these mutations occur in parts of the gene that are responsible for regulating cell growth; the p53 gene for example keeps cells from becoming cancerous.

In XP, the outcome of UV exposure coupled with insufficient DNA repair results in preamature aging and skin cancer in early childhood, even as young as one year old. Some people have a severe sunburn reaction even after a few minutes of indirect sunlight due to the immediate death of skin cells upon exposure to UV. With protection, these skin symptoms can be prevented. Therefore, protecting people with XP from UV is paramount to their health and safety.

Protection is a balance of health risks vs. quality of life. Life with XP is a daily process of weighing risks, controlling environments, measuring protection, and staying informed on research. This page is meant to help you understand UV and how to protect yourself or your child in a way that best fits your needs.

Feedback is welcome and encouraged. Please send comments, questions, or remarks to: william.r.crain@xpresearch.org