MLH1 Promoter Methylation Analysis

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.

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.

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).

Bisulfite converstion, methylation-specific PCR, and gel electrophoresis