About XP

From the Xeroderma Pigmentosum Family Support Group website:

                          WHAT IS XP?

Xeroderma Pigmentosum (or  XP) is a rare inherited disease affecting both males and females. It causes a  person to be extremely sensitive to the damaging effects of ultraviolet  radiation. Undiagnosed and untreated, XP can lead to the early onset of skin cancer  and blindness. In addition, approximately 20% of the people with XP develop  progressive neurological disease.XP is an autosomal recessive disease caused by  mutations in genes that are critical for DNA repair. The body must repair DNA  when it is damaged by harmful external agents such as ultraviolet radiation,  X-rays and chemicals. There are at least eight genes that are critical for this  DNA repair process. If a person is born with any of the eight genes not  functioning correctly, he or she will develop the symptoms of XP. The genes for  XP are: XP-A, XP-B, XP-C, XP-D, XP-E, XP-F, XP-G, and variant XP. Prior to the  discovery of the XP genes themselves, the term “complementation  groups” was used to describe the laboratory variations seen in the cells  of XP patients. The cells were categorized according to the capacity of the  cells to repair DNA after they had been damaged by ultraviolet radiation in the  laboratory. Mutations in the A, C, D, and Variant genes make up over 90% of XP  cases.

How is XP diagnosed?

Often  the first people to suspect that, something is “wrong” are the parents.  Many parents notice that in early infancy around 1-2 years of age their  children will have unusually dark freckles (lentigos) or will have had severe  sunburns after only being in the sun a few minutes. A thorough skin exam by a  dermatologist, along with a small skin biopsy for laboratory testing, is the  standard method for diagnosing XP. Xeroderma Pigmentosum can usually be  conclusively diagnosed by measuring the DNA repair function from the skin cells  obtained from the biopsy.


Early onset of freckling, (before age 2) especially in sun exposed areas of the  skin, severe burns after only a short duration of sun exposure or exposure to  ultraviolet lights. Some people with XP may develop burns even in shady areas.

■Blistering or freckling after minimal sun or ultraviolet exposure

*A dry, premature-aged appearance to the skin and lips

■Photosensitivity of the eyes (become red and sore when exposed to the sunlight)

■Early onset of skin cancer in any skin, including the tip of the tongue

Progressive Neurological Complications

■Developmental disabilities

■High frequency hearing loss,  progressing to deafness

■Loss of previously attained abilities such as walking and talking

What is the treatment for XP?

The main goal of treatment is protection from UV exposure and thus prevention  of the damaging effects it can have on the skin. There is currently no cure for  XP. What is the prognosis? Many patients with xeroderma pigmentosum die at an  early age from skin cancers. However, if a person is diagnosed early, does not  have severe neurological symptoms or has a mild variant, and takes all the  precautionary measures to avoid exposure to UV light, they may survive beyond  middle age. Patients with xeroderma pigmentosum and their families will face  many challenges in daily living. Constant educating and reminding of the need  to protect oneself from sunlight is paramount to the management of xeroderma  pigmentosum.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s