Variant-type xeroderma pigmentosum is the milder subtype of xeroderma pigmentosum (XP), a rare photodermatosis characterized by severe sensitivity to the sun and an increased risk of skin cancer . It is frequently diagnosed in adolescence or during the second decade of life. It is observed in approximately 20% of XP patients and to date has been described in about 50 cases. Those affected have skin lesions , generally in the parts of the body exposed to the sun, which develop skin cancer at 20-30 years of age with a frequency 1,000 times higher than that of the general population. Neurological manifestations are not observed.
Summary
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- 1 Etiology
- 2 Epidemiology
- 3 Clinical description
- 4 Sources
Etiology
The disease is due to mutations in the POLH (XPV) gene (6p21.1-p12) that codes for error-prone DNA polymerase eta (pol-eta) that carries out trans-injury synthesis of radiation photoproducts ultraviolet (UV). Transmission is autosomal recessive.
epidemiology
It is observed in approximately 20% of XP patients and to date has been described in about 50 cases.
Clinical description
Those affected have skin lesions , generally on the parts of the body exposed to the sun , which develop skin cancer at 20-30 years of age with a frequency 1,000 times higher than that of the general population. Neurological manifestations are not observed. Etiology The disease is due to mutations in the POLH (XPV) gene (6p21.1-p12) that codes for error-prone DNA polymerase eta (pol-eta) that carries out the trans-lesion synthesis of the photoproducts of the ultraviolet (UV) radiation. Transmission is autosomal recessive.
