MLH1 Hypermethylation Analysis, Tumor
Use
This test is used as an adjunct to tumor microsatellite instability and mismatch repair protein immunohistochemistry testing when colon or endometrial tumors demonstrate microsatellite instability (MSI-H) and loss of MLH1 protein expression. It helps in distinguishing a somatic versus germline event prior to performing expensive germline testing, and it is also an adjunct to negative MLH1 germline testing in cases where colon or endometrial tumors demonstrate MSI-H and loss of MLH1 protein expression.
Special Instructions
Not provided.
Limitations
Testing tumors other than colon or endometrial for MLH1 hypermethylation has not been fully evaluated, and these specimens are not accepted for testing. Colon cancer is relatively common, and a sporadic colon cancer may occur in a family with hereditary nonpolyposis colorectal cancer (HNPCC). Evaluation of other family members should still be considered in cases with MLH1 promoter hypermethylation if there is high clinical suspicion of HNPCC.
New York Approved
Methodology
PCR-based (PCR)
Biomarkers
No genes
Gene
LOINC Codes
- 97761-1 - MLH1 Methyl Anl Tumor
- 50397-9 - Mol dx interp Bld/T Ql
- 82939-0 - Genetic variant details Bld/T
- 69047-9 - Geneticist review
- 42349-1
- 31208-2 - Specimen source
- 85298-8 - Struct incl in spec Spec
- 80398-1 - Unique ID Current sample
- 18771-6 - Provider signing name
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
Formalin-fixed, paraffin-embedded tissue block
Collection Instructions
Submit a formalin-fixed, paraffin-embedded tissue block with an acceptable amount of tumor tissue.
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Ambient (preferred) |