Test Details
Methodology
Bisulfite converstion, methylation-specific PCR, and gel electrophoresis
Result Turnaround Time
6 - 10 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Hereditary colon cancers of the nonpolyposis type (HNPCC) or Lynch Syndrome (LS) is an inherited cancer syndrome caused by a germline mutation in one of several genes involved in DNA mismatch repair (MMR), including MLH1, MSH2, MSH6 and PMS2, or EPCAM gene. It is estimated to account for 1-3% of colorectal cancer (CRC). Although HNPCC is characterized by abnormal immunohistochemistry for MMR proteins and microsatellite instability (MSI-H), cancers exhibiting abnormal IHC for MLH1 and are MSI-H are most often sporadic (non-inherited) and due to abnormal methylation of the MLH1 gene promoter. Tumors that have the BRAF V600E mutation and MLH1 promoter hypermethylation are almost certainly sporadic, whereas tumors that show neither are most often caused by an inherited mutation. Testing for methylation of the MLH1 promoter can help distinguish sporadic from inherited cancers.
Special Instructions
Please provide a copy of the pathology report. MLH1 testing will be delayed if the pathology report is not received. Please direct any questions regarding this test to customer service at 800-345-4363.
Limitations
In vitro studies indicate that this assay has a sensitivity to detect approximately 1-5% methylated MLH1 promoter.
This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).
Specimen Requirements
Specimen
Formalin-fixed, paraffin-embedded (FFPE) tissue block or slides
Volume
8 pre-cut unstained slides at 5 micron with 1 matching H&E reference slide, or FFPE tissue block
Minimum Volume
Tumor surface area ≥4mm2 tumor area and ≥ 50% tumor content are preferred.
Container
Tissue block and slide container
Storage Instructions
Room temperature
Causes for Rejection
No tumor tissue in FFPE blocks or slides; broken or stained slides
References
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512032 | MLH1 Result | 58416-9 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512033 | Indication | 42349-1 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512034 | Location | N/A | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512035 | Specimen Type | 31208-2 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512036 | Block ID | 57723-9 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512037 | Background | 8251-1 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512039 | Method | 49549-9 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512040 | References | 75608-0 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 512041 | Director Review | 72486-4 | |
| 512031 | MLH1 Methylation Analysis | 58416-9 | 480903 | Microdissection Performed | 8100-0 | |
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512032 | |||||
| Result Code Name | MLH1 Result | |||||
| UofM | ||||||
| Result LOINC | 58416-9 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512033 | |||||
| Result Code Name | Indication | |||||
| UofM | ||||||
| Result LOINC | 42349-1 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512034 | |||||
| Result Code Name | Location | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512035 | |||||
| Result Code Name | Specimen Type | |||||
| UofM | ||||||
| Result LOINC | 31208-2 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512036 | |||||
| Result Code Name | Block ID | |||||
| UofM | ||||||
| Result LOINC | 57723-9 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512037 | |||||
| Result Code Name | Background | |||||
| UofM | ||||||
| Result LOINC | 8251-1 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512039 | |||||
| Result Code Name | Method | |||||
| UofM | ||||||
| Result LOINC | 49549-9 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512040 | |||||
| Result Code Name | References | |||||
| UofM | ||||||
| Result LOINC | 75608-0 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 512041 | |||||
| Result Code Name | Director Review | |||||
| UofM | ||||||
| Result LOINC | 72486-4 | |||||
| Order Code | 512031 | |||||
| Order Code Name | MLH1 Methylation Analysis | |||||
| Order Loinc | 58416-9 | |||||
| Result Code | 480903 | |||||
| Result Code Name | Microdissection Performed | |||||
| UofM | ||||||
| Result LOINC | 8100-0 |