Symptoms

Symptoms

Wide range of symptoms:

Blistering or freckling after minimum sun exposure

Premature aging of skin, lips, eyes, mouth and tongue; with significant increased incidence of cancer in these same areas

Blindness resulting from eye lesions or surgery for skin cancer close to the eyes

Progressive neurological complications including:

• developmental disabilities

• mental retardation

• high frequency hearing loss, progressing to deafness

• de Sanctis-Cacchione syndrome (rare)

XP is very rare. Prevalence is estimated at 1:1,000,000 in the United States. Certain populations have a higher prevalence. For example, in Japan, the prevalence is estimated as 1:40,000. Prevalence is increased in North Africa (Tunisia, Algeria, Morocco, Libya, and Egypt) and the Middle East (Turkey, Israel, and Syria), especially in communities in which consanguinity is common.

Clinical diagnosis possible

Life threatening

• The DNA damage is cumulative and irreversible

• Up to 2000-fold increased risk of skin cancer, or pre-cancerous tumors and mouth and eye tumors

Other disorders associated with defective DNA repair

• Ataxia-Telangiectasia

• Bloom Syndrome

• Cockayne Syndrome

• Fanconi Anemia

• Trichothiodystrophy (TTD)

Other disorders characterized by light sensitivity

• Drug-induced photosensitivity

• Erythropoietic Protoporphyria (EPP)

• Lupus (30% of cases)

• Polymorphous Light Eruption (PLE)

• Porphyria (general)

There is no cure for XP. The DNA damage is cumulative and irreversible. Management is limited to avoidance of exposure to damaging UV radiation by staying indoors with sunlight blocked out, and use of protective clothing, sunscreens and sunglasses. Also, avoid other known carcinogens.