Cases reported "Xeroderma Pigmentosum"

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1/7. A newly identified patient with clinical xeroderma pigmentosum phenotype has a non-sense mutation in the DDB2 gene and incomplete repair in (6-4) photoproducts.

    We report here a patient (Ops1) with clinical photosensitivity, including pigmented or depigmented macules and patches, and multiple skin neoplasias (malignant melanomas, basal cell carcinomas, and squamous cell carcinomas in situ) in sun-exposed areas. These clinical features are reminiscent of xeroderma pigmentosum. As cells from Ops1 showed normal levels in dna repair synthesis in vivo (unscheduled DNA synthesis and recovery of rna synthesis after ultraviolet irradiation), we performed a postreplication repair assay and recovery of replicative DNA synthesis after ultraviolet irradiation to investigate if Ops1 cells belonged to a xeroderma pigmentosum variant pattern. Ops1 cells were normal, but there was an incomplete pattern repair in (6-4) photoproducts in contrast to a normal pattern repair in cis-syn cyclobutane pyrimidine dimers by repair kinetics using the enzyme-linked immunosorbent assay. Moreover, Ops1 cells were defective in a damage-specific DNA binding protein and carried a non-sense mutation in the DDB2 gene. These results suggest that (i) the DDB2 gene is somewhat related to skin carcinogenesis, photoaging skin, and the removal of (6-4) photoproducts; (ii) although it is believed that cyclobutane pyrimidine dimers are the principal mutagenic lesion and (6-4) photoproducts are less likely to contribute to ultraviolet-induced mutations in mammals, Ops1 is one of the ultraviolet-induced mutagenic models induced by (6-4) photoproducts.
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keywords = carcinogenesis
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2/7. xeroderma pigmentosum variant with multisystem involvement.

    BACKGROUND--xeroderma pigmentosum (XP) is a hereditary disorder characterized by recessive inheritance and elevated rates of skin carcinogenesis. There are seven complementation groups (A through G) for which the genetic defect results in a failure to repair dna damage from UV light and sunlight; one group, the variant, fails to replicate UV-damaged DNA correctly. patients in XP groups A, B, D, and G have associated neurologic problems, the most severe being known as the DeSanctis-Cacchione syndrome. OBSERVATIONS--We describe a patient with XP from consanguineous parents who has severe multisystem involvement similar to that of the DeSanctis-Cacchione syndrome. Extensive laboratory investigation showed that cells from this patient exhibit dna replication after irradiation with UV light that is characteristic of the XP variant. The cells also show normal sensitivity to UV light and normal excision repair, consistent with XP variant classification. The presence of the neurologic symptoms is quite unusual in an XP variant. CONCLUSION--Our patient clearly fits into the XP variant category based on normal survival, caffeine toxic reaction, photoproduct excision and repair, and the deficient replication of UV-damaged DNA. This patient seems to be rare, however, among XP variants in displaying severe neurologic symptoms. Because of the consanguineous parents, the possibility that some of this patient's findings are from non-XP-related abnormalities must also be entertained. However, other consanguineous patients with XP variant, eg, XPIOCA, have been described who do not show neurologic abnormalities. In view of the difficulty of defining an XP group from clinical symptoms alone, we urge the term xeroderma pigmentosum variant be used only in the context of the laboratory studies of patients with XP that contain normal repair but deficient semiconservative replication of UV-damaged DNA.
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keywords = carcinogenesis
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3/7. xeroderma pigmentosum: review and report of a case.

    xeroderma pigmentosum is a rare inherited dermatosis that provides insight into the basic mechanism of carcinogenesis. It is a model disorder linking defective dna repair with clinical abnormalities and neoplasia. UV light-induced damage to the skin begins early and results in multiple benign and malignant skin tumors, especially in sun-exposed areas of the head and neck. Oral cancers, primarily squamous cell carcinomas of the anterior third of the tongue, occur with greatly increased frequency. A patient with multiple facial neoplasia and oral manifestations of xeroderma pigmentosum is presented. The role of the dentist in surveillance of oral and perioral structures is emphasized. The dentist is advised against the use of UV light-curing units in these patients because UV-induced epithelial damage may cause dysplasia when dna repair mechanisms are dysfunctional.
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keywords = carcinogenesis
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4/7. Late onset of skin cancers in 2 xeroderma pigmentosum group F siblings and a review of 30 Japanese xeroderma pigmentosum patients in groups D, E and F.

    Sib patients with xeroderma pigmentosum (XP), XP90TO (42 years old, male) and XP92TO (40 years old, female, were assigned to group F by the complementation analysis in hybridized heterodikaryons. The XP90TO and XP92TO fibroblasts exhibited the typical XPF characteristics of a threefold higher sensitivity to the lethal effect of 254 nm UV and a reduced level of 12% unscheduled DNA synthesis (UDS) compared with normal cells. Clinically, both patients manifested moderate to severe acute sun sensitivity by age 8, pigmented freckles by age 10 and skin malignancies at higher ages (6 basaliomas at 42 years in XP90TO; 1 basalioma at 41 years in XP92TO). Despite the still currently sun-sensitive state, the patients showed normal minimal erythema dose (MED) at monochromatic wavelengths of 290, 300 and 305 nm but abnormally delayed peaking of erythema reaction at 48 h after exposure. After irradiation with more than 3 MED, XP92TO showed a long persistence of induced erythema for at least 7 days. A review of the 16 reported XPF patients indicated mild skin manifestations, no neurological abnormalities, and more delayed skin carcinogenesis at a lower frequency than that in XPA patients. In addition, we have collected clinical information from Japanese XP patients in rare complementation groups D and E and reviewed their clinical and photobiological characteristics.
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keywords = carcinogenesis
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5/7. Malignant melanoma of the iris in xeroderma pigmentosum.

    xeroderma pigmentosum is an autosomal recessive, precancerous dermatosis caused by defective repair of ultraviolet-damaged DNA. Characterized clinically by progressive cutaneous pigmentary alterations and tumorigenesis, it serves as a model for ultraviolet carcinogenesis. We describe the clinical and histopathologic findings in a 31-year-old woman with xeroderma pigmentosum and a massive iris melanoma of the left eye. Histologic examination following enucleation revealed diffuse iris replacement by spindle and epithelioid cells with extension into the trabecular meshwork. Evidence of direct extraocular extension was absent, and a metastatic evaluation showed no abnormalities. To our knowledge, this is the first reported case of xeroderma pigmentosum complicated by melanoma of the iris. It provides further evidence suggesting a role for sunlight exposure in the pathogenesis of uveal melanoma.
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keywords = carcinogenesis
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6/7. Delayed sensorineural deafness and skin carcinogenesis in a Japanese xeroderma pigmentosum group D patient.

    A 65-year-old patient with xeroderma pigmentosum (XP), XP77TO, was assigned to complementation Group D by the cell-fusion study and comprised the fifth Group D case in japan. The patient had mild solar sensitivity by age 7, dyspigmentation by 10 years, and he still currently has moderate symptoms. The skin phototest by 290, 300 and 305 nm monochromatic ultraviolet (UV) light revealed a delayed peak of erythema 48 h post-irradiation and lowered minimal erythemal doses. The XP77TO skin fibroblasts, as well as a reference Group D strain, exhibited the same 7-fold higher sensitivity to the lethal effect of 254 nm UV as did normal cells. Unscheduled DNA synthesis (UDS) induced in XP77TO cells by 254 nm UV (10 J/m2) was 42% of normal, falling into the Group D range of 25-50% UDS. In spite of such a similar cellular phenotype, XP77TO developed squamous cell carcinomas at 44 and 65 years of age and audiometric sensorineural deafness in a delayed fashion at advanced age.
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ranking = 4
keywords = carcinogenesis
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7/7. Management of a young patient with xeroderma pigmentosum.

    xeroderma pigmentosum is a group of rare autosomal recessive disorders with defective dna repair that provide insight into the basic mechanism of carcinogenesis. It is the best human model linking clinical abnormalities and neoplasia to carcinogen exposure. We describe a patient with xeroderma pigmentosum and numerous basal cell carcinomas, squamous cell carcinomas, and melanomas treated with radiation therapy, Mohs micrographic surgery, dermabrasion, and isotretinoin prophylaxis.
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keywords = carcinogenesis
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