History:

 Xeroderma Pigmentosa is a multigenic, multiallelic, autosomal recessive disease. There are eight complementation groups: (XP-A to XP-G) and XP variant form (XP-V). The main defect in XP is inability to replicate DNA templates carrying unrepaired DNA damage.

The cinical findings in XP depend on the degree of DNA repair defect. The main set of features include:

•  Mucocutaneous manifestations: skin appears prematurely aged, increased incidence of actinic keratosis, keratoacanthoma, squamous cell carcinoma, basal cell carcinoma, melanoma beginning in childhood and poikiloderma

• Ocular symptoms  include photophobia, conjunctivitis, corneal vascularization, and opacification; malignant tumors may also arise
• Neurologic manifestations: progressive cognitive deterioration, sensorineural deafness, spasticity, ataxia, hyporeflexia  

Prognosis: about two-thirds die by third to fourth decade 

Treatment

• Aggressive avoidance of sun exposure
• High-dose oral isotretinoin
• Excision of cutaneous malignancies
• Imiquimod 5% cream, 5-fluorouracil cream
• Skin screenings every 3 months
• Ophthalmologic evaluation