Büşra Ulucutsoy1, Nilsu Çini2, Oytun Erbaş1

1ERBAS Institute of Experimental Medicine, Illinois, USA & Gebze, Turkey
2Department of Radiation Oncology, Kartal City Hospital, Istanbul, Turkey

Keywords: Cancer, colorectal cancer, Lynch syndrome, microsatellite instability, mismatch repair, mutation


There are sequential repeat sequences that occur spontaneously in deoxyribonucleic acid (DNA). These sequences are called microsatellites, distributed throughout the genome and usually repeat 1-6 base pairs long. In some cases, the Taq (Thermus aquaticus) DNA polymerase enzyme, which is used to read bases during the DNA replication process, causes frameshift mutations by reading the microsatellite repeats incorrectly. These mutations are normally repaired by the mismatch repair (MMR) mechanism; in some cases, a structural defect in the related genes of this mechanism renders the mechanism inactive. Microsatellite instability (MSI) is a structural defect caused by MMR gene inactivation. It has been reported that MSI is frequently observed on various malignancies, which has brought a new perspective to the definition of cancer. MSI is one of the most investigated mechanisms in recent years in order to define the origin, stage, and behavior in the treatment process of cancer. This review discussed the relationship between MSI and Lynch syndrome and colorectal cancer.

Cite this article as: Ulucutsoy B, Çini N, Erbaş O. Microsatellite Instability in Lynch Syndrome and Colorectal Cancers. JEB Med Sci 2021;2(3):375-379.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.