1/212. Molecular studies of Japanese patients with group A xeroderma pigmentosum using polymerase chain reaction and restriction fragment length polymorphism and nonradioactive single strand conformation polymorphism analyses. xeroderma pigmentosum is an autosomal recessive disease characterized by extreme sensitivity of the skin to ultraviolet light, which results in a high incidence of early skin cancer. We report here the molecular analysis of the xeroderma pigmentosum group A complementing genes of five Japanese patients with group A xeroderma pigmentosum and their families, by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis, and by PCR and non-radioactive single strand conformation polymorphism (SSCP) analysis using the Pharmacia PhastSystem. Four of the five patients were found to be homozygous for a known splicing mutation of intron 3. One patient was found to be heterozygous for the splicing mutation of intron 3 and a known nonsense mutation of exon 6. This nonradioactive PCR-SSCP technique was as useful for the molecular diagnosis of patients with group A xeroderma pigmentosum as was PCR-RFLP analysis. ( info) |
2/212. Facial resurfacing in xeroderma pigmentosum with chemical peeling. We describe our experience with two patients with xeroderma pigmentosum who underwent multiple trichloroacetic acid chemical peels. trichloroacetic acid and phenol were used in one case. Until now numerous treatment modalities have been reported. Deep chemical peeling has not been reported before in patients with xeroderma pigmentosum. Chemical peeling is a simple procedure with less associated morbidity. ( info) |
3/212. Molecular analysis of glioma and skin-tumour alterations in a xeroderma-pigmentosum child. xeroderma pigmentosum (XP) is a rare hereditary disease characterized by a very high frequency of skin tumours due to a defect in the nucleotide-excision-repair process. Some of these patients have also been reported to develop internal tumours with higher frequency than the normal population. Reported here are the clinical features and molecular analysis of an XP patient who developed multiple skin cancers as well as a thalamic glioma. Complementation analysis with recombinant retrovirus, cloning efficiency and unscheduled DNA synthesis after UV-C indicate that the patient belongs to the C group. Characterization of the p53 mutations in the 2 tumours of the patient leads to speculation on the aetiological agents involved in tumour initiation. The skin tumour is clearly induced by the presence of unrepaired UVB-induced dna damage on the non-transcribed strand of the p53 gene, while the glioma may be induced by unrepaired DNA lesions produced by free radicals. ( info) |
4/212. The relative expression of mutated XPB genes results in xeroderma pigmentosum/Cockayne's syndrome or trichothiodystrophy cellular phenotypes. The human XPB DNA helicase is a subunit of the dna repair/basal transcription factor tfiih, involved in early steps of the nucleotide excision repair pathway. Two distinct clinical phenotypes, xeroderma pigmentosum associated with Cockayne's syndrome (XP/CS) and trichothiodystrophy (TTD), can be due to mutations in the XPB gene. In the present work, we studied cellular dna repair properties of skin fibro-blasts from two patients mutated in the XPB gene: an XP/CS patient cell (XPCS2BA) with a T296C (F99S) transition and a TTD patient cell (TTD6VI) exhibiting an A355C (T119P) transversion. Both cells are clearly associated with different levels of alterations in their response to UV light. To establish the relationship between the relative expression level of these two alleles and dna repair properties, we transfected SV40-transformed XPCS2BA (XPCS2BASV) cells with a plasmid (pTTD6VI) carrying the XPB-A355C cDNA and examined dna repair properties after UV irradiation (cell survival, unscheduled DNA synthesis and kinetics of photoproduct removal) in stable transfectants. We isolated three clones, which express the XPB-A355C gene (Cl-5) or the XPB-T296C gene (Cl-14) or both genes (Cl-19). This con-stitutes a model system allowing us to correlate the relative expression levels of the XPB-A355C (TTD) and XPB-T296C (XP/CS) genes with various dna repair properties. Overexpression of the XPB-A355C (TTD) gene in an XP/CS cell gives rise to a cellular phenotype of increased repair similar to that of TTD6VI cells, while equal expression of the two mutated genes leads to an intermediate cellular phenotype between XP/CS and TTD. ( info) |
5/212. xeroderma pigmentosum variant associated with multiple cancers. A 62-year-old Japanese man with xeroderma pigmentosum (XP) variant is reported. The patient had developed at least 6 basal cell carcinomas, a squamous cell carcinoma, and a malignant melanoma on sun-exposed areas, and an atypical carcinoid on the right lung. In vivo phototesting showed a normal response. The minimal erythema dose of ultraviolet B (UVB) was not lowered and no delayed peaking of the erythema reaction was observed. His skin fibroblasts exhibited higher sensitivity to UV irradiation, but a normal level of unscheduled DNA and rna synthesis. Cell fusions with XP group A, C, D, E, F, and G cells after UV irradiation were all complemented. Previous reports together with this case suggest that older XP variant patients have a high frequency of not only skin cancers, but also internal malignancies. ( info) |
6/212. Clinical remission of xeroderma pigmentosum-associated squamous cell carcinoma with isotretinoin and chemotherapy: case report. We report the case of a 7-year old boy with xeroderma pigmentosum and a large squamous cell carcinoma of the cheek. He received a combination of isotretinoin (1 mg/kg/day) and chemotherapy for a period of 3 months and showed complete remission of the tumor. Treatment modalities of malignancies in xeroderma pigmentosum are reviewed and discussed in relation to the literature. The advantages of our protocol were emphasized because of the rapid improvement in a short time with minimal side effects. ( info) |
7/212. 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. ( info) |
8/212. Cancer protection in xeroderma pigmentosum variant (XP-V). We describe herein a brother and sister diagnosed with xeroderma pigmentosum variant (XP-V) in early adult life, who presented with increased sensitivity to sunlight and with cutaneous carcinomas on sun-damaged skin. The 27-year-old male farmer (Case 1.) was diagnosed with advanced squamous cell carcinoma (SCC) and multiple actinic lesions. Surgical removal of these lesions was performed. Three months later he died of multiple pelvic metastases of SCC. His 29-year-old sister (Case 2.) was operated on for different tumors, histologically SCC-s or basal cell carcinomas (BCC), or praecancerous conditions many times. After a two year interval she was treated with low dose isotretinoin (2 mg/body weight). diagnosis of XP-V was based on unscheduled DNA analysis (USD) and on clinical symptoms. We observed that during the long lasting isotretinoin treatment the tumor frequency dropped to a quarter. Therefore, the isotretinoin treatment seems to be a good approach for cancer prevention in conditions with high predisposition to skin cancer, such as in XP-V. ( info) |
| OBJECTIVE: to evaluate the probable presence of otorhinolaryngological pathology accompanied by head and neck region skin findings in patients with xeroderma pigmentosum. methods: a total of 19 patients with xeroderma pigmentosum were investigated for otorhinolaryngological findings. The patients gave their anamnesis and underwent physical examination, audiological tests and endoscopic examination. RESULTS: various malignancies developed in 14 patients on the sun-exposed areas of the head and neck region. Multiple malignancies were found in six of them. There was no other pathological condition secondary to this rare clinical entity. CONCLUSION: xeroderma pigmentosum causes skin lesions. Some otolaryngological findings such as rhinitis, sinusitis etc. were thought to be coincidental. ( info) |
10/212. Two unusual tumors in a patient with xeroderma pigmentosum: atypical fibroxanthoma and basosquamous carcinoma. xeroderma pigmentosum (XP) is a rare autosomal recessive disease, characterized by a genetic defect in dna repair. The consequence is a high incidence of skin cancers on sun-exposed cutaneous surfaces of affected children. First lesions appear in the first years of life: telangiectasia, actinic keratosis and keratoacanthomas. Squamous cell and basal cell carcinomas are the most frequent neoplasms. We report the case of a 6-year-old girl affected with XP, who developed two unusual tumors: an atypical fibroxanthoma and a basosquamous carcinoma. In both tumors, immunohistochemical study showed abnormal accumulation of the p53 protein, suggesting the presence of mutation of the p53 tumor suppressor gene. Such p53 mutations may be ultraviolet (UV)-induced, as they are frequently observed in tumors occurring in XP. ( info) |