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Test ID BRMLH MLH1 Hypermethylation and BRAF Mutation Analysis, Tumor

Useful For

An adjunct to MSI / Microsatellite Instability (MSI), Tumor and IHC / Mismatch Repair (MMR) Protein Immunohistochemistry Only, Tumor testing, when colon 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 tumor from the same patient demonstrates MSI-H and loss of MLH1 protein expression

Genetics Test Information

If this test is ordered in conjunction with the MLH1 immunostain (IHC / Mismatch Repair [MMR] Protein Immunohistochemistry Only, Tumor) and MSI (MSI / Microsatellite Instability [MSI], Tumor), this test will only be performed when clinically indicated.

Profile Information

Test ID Reporting Name Available Separately Always Performed
PBMLH MLH1 Hypermethylation/BRAF Mutation No Yes

Additional Tests

Test ID Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill Only) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
BBRAF BRAF Analysis Yes, (order BRAFT) No
BMLHH MLH1 Hypermethylation Analysis Yes, (order ML1HM) No

Testing Algorithm

When this test is ordered, BRAF analysis and MLH1 hypermethylation analysis will always be performed. The exception would be if the tissue origin is an endometrial tumor; in those cases MLH1 hypermethylation analysis will be performed. If an endometrial tumor does not show loss of MLH1 by immunohistochemistry, we could still run BRAF and not do MLH1 hypermethylation.


When this test is ordered, slide review will always be performed at an additional charge.


See Lynch Syndrome Testing Algorithm in Special Instructions.

Method Name

Polymerase Chain Reaction (PCR)

Reporting Name

MLH1 Hypermethylation/BRAF Mutation

Specimen Type


Advisory Information

This test is not recommended as a first-tier screening measure for hereditary nonpolyposis colon cancer (HNPCC). Please refer to MSI / Microsatellite Instability (MSI), Tumor and IHC / Mismatch Repair (MMR) Protein Immunohistochemistry Only, Tumor. Testing will only be performed on colon tumors demonstrating microsatellite instability or immunohistochemistry results indicating loss of MLH1 protein expression. 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 both tumor and normal tissue.

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Weekly; Varies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

Slide Review

88381-Microdissection, manual


81210-BRAF (v-raf murine sarcoma viral oncogene homolog B1) (eg, colon cancer), gene analysis, V600E variant, if appropriate

81288-MLH1 promoter methylation analysis, if appropriate

LOINC Code Information

Test ID Test Order Name Order LOINC Value
BRMLH MLH1 Hypermethylation/BRAF Mutation In Process


Result ID Test Result Name Result LOINC Value
53223 Result Summary 50397-9
53224 Result 82939-0
53225 Interpretation 69047-9
53226 Specimen 31208-2
53227 Source 31208-2
53228 Tissue ID 80398-1
55139 Method 49549-9
54921 BRAF Analysis No LOINC Needed
54440 MLH1 Hypermethylation Analysis No LOINC Needed
53229 Released By 18771-6

NY State Approved


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 U.S. Food and Drug Administration.


1. Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519) in Special Instructions

2. If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.