When Caren and Dan Mahar of New York learned their daughter Katie had been afflicted with xeroderma pigmentosum, they didn't know where to turn. Individuals with XP must avoid the sun and bright lights because their bodies do not have the ability to repair skin exposed to ultraviolet rays, so what would be normal exposure to sunlight for anyone else can be catastrophic for a person with XP.

The odds of an XP patient getting cancer are great if exposed to ultraviolet light. They must therefore adjust their lifestyle to this condition by staying indoors during daylight hours. While indoors, special window shades and low-wattage lights are necessary for XP sufferers. At least 150 people in the United States and 3,000 people worldwide are afflicted with this disease. There is no known cure.

In 1995, the Mahars founded the XP Society to help patients and families dealing with the disease. The society supports medical research for finding a cure as well as providing information to XP patients. The biggest single act of the XP Society is its Camp Sundown, where patients and their families gather twice a year. The hours of the camp are structured so all activities take place at night when it is safe for XP patients to be outside. Without a dime of federal funding, the XP Society has waged a sustained, organized campaign of information and support for XP sufferers. The society recently received a $10,000 donation from Brad and Kimberly Williams-Paisley.

Caren Mahar, director of the XP Society, took a moment to answer some questions about ongoing research for a cure for XP and the challenges of fund raising.

Can you talk about some of the ongoing research for finding a cure for XP? What is the funding status of these research projects?

There are many different types of studies going on right now that may help cure XP in the not-too-distant future. From ultraviolet light studies on cells of XP and control, we are able to tell how fast cells die when exposed to UV radiation. This type of study also helps determine the type of XP (XPA, XPB, XPC, etc.) a patient has.

Research has been going on in France for a long time on delivering a correction to the defective gene using  retrovirals to turn an XP gene "normal". On Long Island, a company dedicated to curing skin cancer (and XP has the largest amounts of skin cancer in the population at 2000 times the rate) has created a DNA damage repair creme that repairs damage done to skin cells from sunlight, thus preventing future skin cancers. This is on a fast track with the FDA now after many years of clinical trial with XP patients.

Just recently, Transgenic mice bred in the lab have achieved the physical characteristics of XP patients who have neurological implications. This may better help us understand how approximately 20% of all XP patients lose the ability to see, hear, walk and talk. The XP disease was discovered in 1860 by Kaposi, and in about 1960, Dr James Cleaver, still at UCSF, discovered that ultraviolet light was what caused the cell mutations that would lead to cancers in XP patients. XP research is used, because XP is an aging disease; speeding up the end result in research projects, in studies relating to many diseases including but not limited to renal transplant issues, skin cancer (which is internationally epidemic), Alzheimer's, and Parkinson's disease.