			Home About us Contact

MSH2 Mutation (msh2 + mutation)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Malignant melanoma in patients with hereditary nonpolyposis colorectal cancer

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2008
G. Ponti
Summary Background, Malignant melanoma (MM) is the most aggressive skin cancer. Most MMs are sporadic, and in this setting an association with mismatch repair (MMR) gene mutations, typical of hereditary nonpolyposis colorectal cancer (HNPCC) tumours, has been proposed. Objectives, To characterize clinically and/or by molecular biology the patients with MM belonging to a cohort of 60 kindreds with HNPCC. Methods, Patients with HNPCC with a diagnosis of MM were studied by immunohistochemistry (IHC) on tumour tissue using antibodies to MLH1, MSH2, p16, ,-catenin and E-cadherin, and by direct sequencing of MMR genes on germline DNA, and BRAF and NRAS on somatic DNA extracted from MM. Results, Nine cutaneous MMs were detected in the tumour spectrum of eight families with HNPCC. The median age at diagnosis was 46 years. In one HNPCC family the diagnosis of MM was made in two first-degree relatives fitting the clinical definition of familial melanoma. IHC and sequencing analysis showed an MSH2 mutation in one patient with MM. Conclusions, Dermatological surveillance should be recommended to families in which MM is diagnosed in at least one member, especially at a young age. The combination of MMR gene mutations and abnormalities of p16 or other molecular pathways is needed to induce melanocytic carcinogenesis in a familial setting as well as in sporadic MM. [source]

Pathologic features of endometrial carcinoma associated with HNPCC

CANCER, Issue 1 2006
A comparison with sporadic endometrial carcinoma
Abstract BACKGROUND Endometrial carcinoma is a common malignancy in hereditary nonpolyposis colorectal carcinoma (HNPCC). Like colon carcinoma, endometrial carcinoma is diagnosed at an earlier age in women with HNPCC. In contrast to colon carcinoma, the pathologic features of endometrial carcinoma in HNPCC have not been studied in detail. It was the purpose of this study to pathologically characterize a series of HNPCC associated endometrial carcinomas. METHODS Fifty women with HNPCC and endometrial carcinoma were analyzed from four different hereditary cancer registries. H&E stained slides and pathology reports were reviewed for clinically important pathologic features of endometrial carcinoma. These results were compared with those for two different groups of sporadic endometrial carcinoma , women younger than age 50 years (n = 42) and women of all ages with tumors demonstrating microsatellite instability (MSI-high) secondary to methylation of MLH1 (n = 26). RESULTS Nearly one-fourth of HNPCC patients in this study had endometrial tumors with pathologic features that would require adjuvant therapy after hysterectomy. There was a trend toward the HNPCC patients having more nonendometrioid tumors; all of these patients were carriers of MSH2 mutations. Such nonendometrioid tumors were extremely rare in the MLH1 methylated group. A subset of MLH1 methylated sporadic tumors demonstrated a unique, ,undifferentiated' histology that was not observed in HNPCC or the young group. CONCLUSION Data suggest a genotype,phenotype relation in which microsatellite instability resulting from MLH1 methylation is almost exclusively associated with classical or ,undifferentiated' endometrioid tumors, whereas microsatellite instability secondary to MSH2 mutation can result in a more variable histologic spectrum of endometrial carcinoma. Cancer 2006. © 2005 American Cancer Society. [source]

Eight novel MSH6 germline mutations in patients with familial and nonfamilial colorectal cancer selected by loss of protein expression in tumor tissue,,

HUMAN MUTATION, Issue 3 2004
Jens Plaschke
Abstract Germline mutations in mismatch repair (MMR) genes, predominantly in MLH1 and MSH2, are responsible for hereditary nonpolyposis colorectal cancer (HNPCC), a cancer-susceptibility syndrome with high penetrance. In addition, MSH6 mutations have been reported to account for about 10% of all germline mismatch repair (MMR) gene mutations in HNPCC patients, and have been associated with a later age of onset of the disease compared to MLH1 and MSH2 mutations. Here, we report eight novel germline mutations in MSH6. The patients were selected by having developed tumors with loss of MSH6 protein expression. All tumors showed high-level microsatellite instability (MSI-H). Seven mutations resulted in premature stop codons, comprised of two nonsense mutations (c.426G>A [p.W142X], c.2105C>A [p.S702X]), two insertions (c.2611_2614dupATTA [p.I872fsX10], c.3324dupT [p.I1109fsX3]) and three deletions (c.1190_1191delAT [p.Y397fsX3], c.1632_1635delAAAA [p.E544fsX26], c.3513_3514delTA [p.1171fsX5]). In addition, an amino acid substitution of an arginine residue (c.2314C>T [p.R772W]) conserved throughout a wide variety of mutS homologs has been found in a patient not fulfilling the Bethesda criteria for HNPCC. Our results emphasize the suitability of IHC as a pre-selection tool for MSH6 mutation analysis and the high frequency of germline mutation detection in patients with MSH6 -deficient tumors. In addition, our findings point towards a broad variability regarding penetrance associated with MSH6 germline mutations. © 2004 Wiley-Liss, Inc. [source]