Xeroderma pigment hereditary Disease that affects the skin and Eyes.
The first descriptions of the disease are in the dermatology textbook, published in 1874, “about the disease of the skin, including rashes,” London – New Sydenham Society. Hebra F, Kaposi M. The term “Xeroderma Pigment sum” was coined by the Hungarian dermatologist Moritz Kaposi want to identify with her, a condition characterized by skin and hair pigmentation. Inherited disorder, autosomal recessive, is to eliminate the extreme sensitivity to light, early and severe damage to eyes and skin determines the label. The incidence is 1:250000 in Europe and the United States, while Japan, the proportion of 1:40,000. Could cause in a child with XP, but a brief exposure to sunlight, skin burns with a slow resolution, therefore, essential to avoid UV radiation and the effects of time of exposure are cumulative. The skin manifestations that characterize the disease, such as age spots, dry skin, atrophic lesion, Kerasotes, bubbles, you see, ten years ago, cancer of the skin. Tumor lesions, as determined by an error in the DNA repair mechanism, usually develop on the face and other body parts exposed to the sun, including eyes, lips and tongue. The three most common cancers of the skin (squalors cell basal cell carcinoma and melanoma) are under XP, if we understand the importance of continuous monitoring of the patient may be anxious to go to the immediate removal of a skin growth. It can be at eye level, from the earliest stages of the disease in approximately 80% of patients photophobia, conjunctivitis, dermatitis, corneal opacity, blindness, lead to the appearance of tumor growths even type. Note that the skin is affected after the first six months of life are normal at birth. Less than 40% of patients survive for twenty years, who develop skin cancer Many early. By contrast, patients with a mild form of the disease than the average age. About events in the eyes and skin, 20% of XP patients with neurological problems: deafness, microcephaly, spasticity, ataxia, chorea, ophthalmoplegia, and mental retardation described. The combination of XP, hypogonadism, short stature, cerebella ataxia and mental retardation syndrome characterized De Sanctus and Caching. The reasons for the determination of XP will be seeking change in the DNA repair mechanism. In normal conditions, the modified DNA fragment removed and replaced by a fragment of the synthesis of a mechanism called “excision repair”. The basis of the failure of XP is in the nucleotide excision repair, TNS (TNS Global genome GG – TC Transcription Together NER), causing a deficiency in repairing DNA damaged by ultraviolet radiation. In essence, those affected by XP cells (fibroblasts, lymphocytes, etc …) cannot repair the damage caused by ultraviolet radiation. There are eight types of xeroderma pigment sum: Each type is characterized by various genetic changes in the DNA repair system. Diagnostic tests can be performed in the laboratory, measuring the lack of DNA repair. This test is performed with skin or blood of patients. There is no cure for xeroderma pigment sum, although these procedures implemented to reduce the symptoms: protection against ultraviolet radiation, frequent monitoring of the skin and eyes, rapid removal of tumors of the skin, neurological, and, last but not least, psycho-social support of the mission, noting that children are forced to retire to live at night to avoid the sun.