Microsatellite Instability
ORDER CODE: TMSIORDERING
SPECIMEN
PROCESSING
RESULTS
Test Code
| SHC TEST CODE | LPCH TEST CODE |
|---|---|
| LABTMSI | LAB3008 |
Synonyms
Clinical Utility
Microsatellite instability (MSI) is detected in 90% of colon cancers that are part of the Hereditary Non-Polyposis Colorectal Carcinoma (HNPCC) syndrome, and in 15% of sporadic colorectal carcinomas. It is the consequence of germline mutation(s) in or somatic inactivation of mismatch repair genes, such as MLH1, MSH2, MSH6, or PMS2. Due to their repetitive sequence composition, microsatellite sequences are especially vulnerable. This assay is based on multiplex PCR amplification of 5 microsatellites: BAT-25, BAT-26, MONO-27, NR-21, and NR-24. If there is a difference in the length of a certain microsatellite in the patient’s normal and tumor samples, the microsatellite is considered unstable. If two microsatellite loci (of 5) are unstable, the tumor is designated microsatellite instability high (MSI-H). If only one locus is unstable, the tumor is considered microsatellite instability low (MSI-L), and if no loci are unstable, the tumor is designated microsatellite stable (MSS).
CPT Code
Volume
| REQUESTED VOLUME | MINIMUM VOLUME(PEDIATRIC) |
|---|---|
| Varies | Varies |
Specimen Stability
| TEMPERATURE | |||
|---|---|---|---|
| SPECIMEN TYPE | ROOM TEMP | REFRIGERATED | FROZEN |
| FFPE tissue, tumor and normal | Not Available | Not Available | Not Available |
Sample should be kept at refrigerator temperatures and arrive in lab within 48 hours of collection. Ship on ice.
Department
Standard Run Time(s)
Turnaround Time
| ROUTINE | STAT |
|---|---|
| 7-14 days | 7-14 days |
Methodology
Test Code
| SHC TEST CODE | LPCH TEST CODE |
|---|---|
| LABTMSI | LAB3008 |
Synonyms
Clinical Utility
Microsatellite instability (MSI) is detected in 90% of colon cancers that are part of the Hereditary Non-Polyposis Colorectal Carcinoma (HNPCC) syndrome, and in 15% of sporadic colorectal carcinomas. It is the consequence of germline mutation(s) in or somatic inactivation of mismatch repair genes, such as MLH1, MSH2, MSH6, or PMS2. Due to their repetitive sequence composition, microsatellite sequences are especially vulnerable. This assay is based on multiplex PCR amplification of 5 microsatellites: BAT-25, BAT-26, MONO-27, NR-21, and NR-24. If there is a difference in the length of a certain microsatellite in the patient’s normal and tumor samples, the microsatellite is considered unstable. If two microsatellite loci (of 5) are unstable, the tumor is designated microsatellite instability high (MSI-H). If only one locus is unstable, the tumor is considered microsatellite instability low (MSI-L), and if no loci are unstable, the tumor is designated microsatellite stable (MSS).
CPT Code
close ORDERING
Volume
| REQUESTED VOLUME | MINIMUM VOLUME(PEDIATRIC) |
|---|---|
| Varies | Varies |
Specimen Stability
| TEMPERATURE | |||
|---|---|---|---|
| SPECIMEN TYPE | ROOM TEMP | REFRIGERATED | FROZEN |
| FFPE tissue, tumor and normal | Not Available | Not Available | Not Available |
Sample should be kept at refrigerator temperatures and arrive in lab within 48 hours of collection. Ship on ice.
close SPECIMEN
Department
Standard Run Time(s)
Turnaround Time
| ROUTINE | STAT |
|---|---|
| 7-14 days | 7-14 days |
close PROCESSING
Methodology
close RESULTS