MGMT Methylation Status
Indication
O6-Methylguanine-DNA Methyltransferase (MGMT) is a DNA repair enzyme that removes alkyl adducts from the O6 position of guanine. Epigenetic silencing of the MGMT gene by promoter methylation has been associated with decreased production of the enzyme which may compromise this DNA repair mechanism and may predict response to alkylating agent therapy (such as temozolomide). In addition, MGMT gene promoter methylation status is a prognostic biomarker in pediatric and adult patients with glioblastoma. Therefore, testing for MGMT gene promoter methylation has become an important assay for identifying patients who will have a better overall prognosis and may respond better to alkylating agents.
Methodology
Bisulfite conversion of DNA purified from formalin-fixed, paraffin-embedded tumor tissue, followed by parallel amplification of the methylated MGMT gene promoter and a portion of the beta-actin, ACTB, gene as a loading reference using methylation-specific real-time PCR (MS-PCR)
Test Parameters
This assay will determine methylation status of eight CpG islands within the MGMT gene promoter. Methylation status will be classified as methylated, unmethylated or undetermined. The lower limit of detection (analytical sensitivity) of this assay is 5% of methylated DNA in the sample tested.
Turnaround Time
10 days
Sample Requirements
Formalin-fixed, paraffin embedded tissue blocks containing adequate amounts of tumor to be analyzed (see above sensitivity), with areas to be tested indicated.
Please provide a copy of the corresponding pathology report.
CPT Codes
81287
Additional charges may apply for tissue extraction.
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.