Bashyam, M.D. and Kotapalli, V. and Raman, R. and Chaudhary, A.K. and Yadav, B.K. and Gowrishankar, S. and Uppin, S.G. and Kongara, R. and Sastry, R.A. and Mohana Vamsy, C. and Patnaik, S. and Rao, S. and Dsouza, S. and Desai, D.C. and Tester, A. (2015) Evidence for presence of mismatch repair gene expression positive Lynch syndrome cases in India. Molecular Carcinogenesis, 54 (12). pp. 1807-1814. ISSN 0899-1987

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Abstract

Lynch syndrome (LS), the most common form of familial CRC predisposition that causes tumor onset at a young age, is characterized by the presence of microsatellite instability (MSI) in tumors due to germline inactivation of mismatch repair (MMR) system. Two MMR genes namely MLH1 and MSH2 account for majority of LS cases while MSH6 and PMS2 may account for a minor proportion. In order to identify MMR genes causing LS in India, we analyzed MSI and determined expression status of the four MMR genes in forty eight suspected LS patient colorectal tumor samples. Though a majority exhibited MSI, only 58% exhibited loss of MMR expression, a significantly low proportion compared to reports from other populations. PCR-DNA sequencing and MLPA-based mutation and exonic deletion/duplication screening respectively, revealed genetic lesions in samples with and without MMR gene expression. Interestingly, tumor samples with and without MMR expression exhibited significant differences with respect to histological (mucin content) and molecular (instability exhibited by mononucleotide microsatellites) features. The study has revealed for the first time a significant proportion of LS tumors not exhibiting loss of MMR expression.

Item Type:	Article
Subjects:	Genetics Molecular Biology
Depositing User:	Users 2 not found.
Date Deposited:	17 May 2015 03:50
Last Modified:	15 Dec 2015 04:24
URI:	http://cdfd.sciencecentral.in/id/eprint/42

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