Microsatellite Instability MSH2
Test Code
I MSH2
Test Synonyms
Melanocyte Stimulating Hormone
Associations
Heridatory CRC; Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC)
Methodology
Immunohistochemistry
clone FE11
clone FE11
CPT Codes
88342 each marker
Turnaround Time
Less than 2 days
Specimen Requirements
- Surgical samples received in 10% neutral buffered formalin
- Formalin fixed paraffin embedded tissue
- Previously prepared pathology materials (slides,smears, blocks or other samples)
Specimen Stability
Indefinitely at room temperature
Storage & Handling
Ship ambient. In extreme hot weather, ship with a cool pack.
Causes for Rejection
Inadequate fixation; Improper labeling
Related Content
MSI profile; KRAS; BRAF;CellSearch CTC
Description
MSH2 is a 100 kDa nuclear antigen and encodes a protein of 934 amino acids. The MSH2 gene is one of only 4 known to encode proteins involved in the repair of mismatch nucleotides following DNA replication or repair. Mutations in the MSH2 gene contribute to the development of sporadic colorectal carcinoma. MSH2 mutations are responsible for 50% of hereditary non-polyposis colorectal cancer (HNPCC). The repair of mismatch DNA is essential to maintaining the integrity of genetic information over time. An alteration of microsatellite repeats is the result of slippage owing to strand misalignment during DNA replication and is referred to as microsatellite instability (MSI). These defects in DNA repair pathways have been related to human carcinogenesis. MSH-2 is involved in the initial cognition of mismatch nucleotides during the replication mismatch repair process. It is thought that after MSH2 binds to a mismatched DNA duplex it is joined by a heterodimer of MLH1 and PMSH, which together help facilitate the later steps in mismatch repair.
References
- Thibodeau SN et al.(1996). Altered expression of hMSH2 and hMLH1 in tumors with microsatellite instability and genetic alterations in mismatch repair genes. Cancer Res 5(21):4836-40.
- Piñol V. et al. (2005). Accuracy of Revised Bethesda Guidelines,Microsatellite Instability, and Immunohistochemistry for the Identification of Patients With Hereditary Nonpolyposis Colorectal Cancer. JAMA. 293:1986-1994
- Gatalica Z, Torlakovic E.(2008). Pathology of the hereditary colorectal carcinoma. Fam Cancer.7(1):15-26.
- Boland, C.R., et al.(1998). A National Cancer Institute Workshop on Microsatellite Instability for cancer detection and familial predisposition: development of international criteria for the determination of microsatellite instability in colorectal cancer. Cancer Research.58(22): 5248-5257.
