Loss of mismatch repair gene function in Lynch Syndrome affects what process?

Loss of mismatch repair gene function in Lynch Syndrome primarily affects error correction during DNA replication. Mismatch repair (MMR) is a crucial mechanism for correcting errors that occur during DNA replication, such as insertions, deletions, and mispaired bases. When this repair system is compromised, as it is in Lynch Syndrome, the fidelity of DNA replication decreases, leading to an accumulation of mutations. This accumulation can give rise to various forms of cancer, particularly colorectal and endometrial cancers.

While microsatellite instability, which can be analyzed during testing, is a consequence of deficient mismatch repair, it is not the primary process that is affected by the loss of mismatch repair function. Microsatellite instability is often used as a marker to indicate the presence of MMR deficiency but does not directly describe the fundamental process that is impaired. Similarly, protein synthesis is not directly impacted by mismatch repair, and cell division regulation, while important in cancer pathology, is not the direct result of impaired error correction during replication.