MLH1 Promoter Methylation
Also known as: MLH1 PCR
Use
MLH1 promoter methylation testing is used primarily to identify sporadic microsatellite unstable tumors, such as colorectal and endometrial cancers. MLH1 methylation is common in these sporadic tumors and is infrequently seen in Lynch syndrome (hereditary non-polyposis colorectal cancer, or HNPCC). The presence of MLH1 methylation in a tumor is suggestive of a sporadic cancer rather than Lynch syndrome, though rare cases of Lynch syndrome-associated MLH1 methylation have been reported. It aids in distinguishing these types in conjunction with other clinical evaluations.
Special Instructions
Include the surgical pathology report with specimen submissions. If multiple specimens (blocks or slides) are sent, please accompany with an order comment for pathologist selection or individual orders for each sample. A Pathologist Block Selection Fee (ARUP test code 3002076) may apply.
Limitations
This test is specifically designed to detect methylation at locations targeted by specific primers and probes; other methylation sites will not be detected. It should not be used in isolation to determine malignancy and is not intended for minimal residual disease detection. Negative results do not preclude the presence of conditions associated with MLH1 methylation elsewhere.
New York Approved
Methodology
PCR-based (Real-time PCR)
Biomarkers
Result Turnaround Time
7-12 days
Related Documents
For more information, please review the documents below
Specimen
Tumor Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Collection Instructions
Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue. Transport tissue block or 5 unstained 5-micron slides in a tissue transport kit available online.
Storage Instructions
Store at room temperature; refrigeration is acceptable. Ship in cooled container during summer.
Causes for Rejection
Specimens containing less than 25 percent tumor, any fixative other than 10 percent neutral buffered formalin, or bone specimens submitted in non-EDTA decalcifier.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinitely |
| Refrigerated | Indefinitely |
| Frozen | Unacceptable |