MMR Gene Unclassified Variants Database

Curators: Rolf Sijmons and Robert Hofstra, dept. of Genetics, University Medical Center Groningen, Groningen, The Netherlands

This database is a work in progress. It contains information from functional assays and other type of data to support the interpretation of MMR gene unclassified variants. One of its goals is to support the international UV interpretation committees of InSiGHT ( in collaboration with the Human Variome Project (HVP).

Classifications of the outcome of each of the individual functional tests or in silico analyses are given for research purposes only. For additional information on MMR gene mutations, we would like to refer the reader to the new mutation database of InSiGHT. The original InSiGHT database has been merged with the mismatch repair genes variant database of the Memorial University of Newfoundland ( and our database. This merged database can be found at . Another resource is the HGMD (  (most up-to-date information not freely available).

date of last update: August 15th, 2023

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April 2024

We are excited to announce our research on genetics and THC detoxification.

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August 2023.

We are happy to report that during the next few months we will expand the database contents with recently published MMR functional assay & in-silico analysis papers.

General remarks

Reference sequences for the genes in this database: MLH1MSH2MSH6PMS2MLH3
Mutation nomenclature used follows the standard reported here:

Reference: Ou J, Niessen RC, Vonk J, Westers H, Hofstra RMW, Sijmons RH. A database to support the interpretation of human mismatch repair gene variants. Human Mutation 2008;29:1337-1341

If you find any mistakes in this database (e.g. typos or misinterpretation of your published data), then please contact us.

Part of the research for this database was financially supported by a grant from the Dutch Cancer Society (RUG 2002-2678). The technical development of the web site was financially supported by a grant from the European Union 6th Framework (MMR-related Cancer Project). Curation of this database is financially supported by the department of Genetics of the University Medical Center Groningen.