Test Code ML1HM MLH1 Hypermethylation Analysis, Tumor
Ordering Guidance
This test is not recommended as a first-tier screening measure for hereditary nonpolyposis colon cancer. For more information see TMSI / Microsatellite Instability, Tumor and IHC / Mismatch Repair (MMR) Protein Immunohistochemistry Only, Tumor.
Testing will only be performed on colon or endometrial tumors demonstrating loss of MLH1 protein expression by immunohistochemistry.
Mayo Clinic's preferred screening test includes both MLH1 promoter hypermethylation and BRAF V600E testing. Order BRMLH / MLH1 Hypermethylation and BRAF Mutation Analysis, Tumor.
Extracted DNA from tissues is not an acceptable specimen type.
Necessary Information
Pathology report must accompany specimen in order for testing to be performed.
Specimen Required
Specimen Type: Tissue block or slide
Collection Instructions:1. Submit formalin-fixed, paraffin-embedded tissue block (preferred) or 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides (5-micron thick sections) of the tumor tissue.
2. Sections should contain tumor tissue.
Forms
1. Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519)
2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-Gastroenterology and Hepatology Client Test Request (T728)
-Oncology Test Request (T729)
Useful For
An adjunct to TMSI / Microsatellite Instability, Tumor and IHC / Mismatch Repair (MMR) Protein Immunohistochemistry Only, Tumor when colon or endometrial tumor demonstrates microsatellite instability (MSI-H) and loss of MLH1 protein expression, to help distinguish a somatic versus germline event prior to performing expensive germline testing
An adjunct to negative MLH1 germline testing in cases where colon or endometrial tumor demonstrates MSI-H and loss of MLH1 protein expression
Additional Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
SLIRV | Slide Review in MG | No, (Bill Only) | Yes |
Testing Algorithm
When this test is ordered, slide review will always be performed at an additional charge.
For more information see Lynch Syndrome Testing Algorithm.
Special Instructions
Method Name
Polymerase Chain Reaction (PCR)
Reporting Name
MLH1 Hypermethylation Analys, TumorSpecimen Type
VariesSpecimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Ambient (preferred) | ||
Frozen | |||
Refrigerated |
Reject Due To
Specimens that have been decalcified (all methods) Specimens that have not been formalin-fixed, paraffin-embedded Bone marrow in EDTA |
Reject |
Reference Values
An interpretative report will be provided.
Day(s) Performed
Varies
Report Available
7 to 14 daysPerforming Laboratory

Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81288
88381
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ML1HM | MLH1 Hypermethylation Analys, Tumor | 97761-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
53299 | Result Summary | 50397-9 |
53300 | Result | 82939-0 |
53301 | Interpretation | 69047-9 |
53302 | Reason for Referral | 42349-1 |
53303 | Specimen | 31208-2 |
53304 | Source | 85298-8 |
54447 | Tissue ID | 80398-1 |
53305 | Released By | 18771-6 |
Secondary ID
35494Specimen Minimum Volume
See Specimen Required