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Alternative Name
KRAS Gene Sequencing, KRAS Exons 2-4 (includes G12C mutation)
Test Description

Bi-directional sequencing of exons 2, 3, and 4 of the KRAS (includes G12C mutation) gene including codons 12, 13, 59, 61, 117, and 146. High-sensitivity sequencing is used for enhanced detection of mutations in codons 12 and 13. Testing is available separately or in combination with BRAF, HRAS and NRAS in the RAS/RAF Panel.

Clinical Significance

Testing is recommended in colorectal cancer as mutations are associated with resistance and shorter overall survival with EGFR-antagonist therapies such as cetuximab or panitumumab. Testing in non-small cell lung cancer may provide prognostic information and predict poor response to EGFR tyrosine kinase inhibitors.

Specimen Requirements
  • FFPE solid tumor tissue: Paraffin block is preferred. Alternatively, send 1 H&E slide plus 5-10 unstained slides cut at 5 or more microns. Please use positively-charged slides and 10% NBF fixative. Do not use zinc fixatives.
  • Fine needle aspirate (FNA): FFPE cell blocks are acceptable. Requisition must note specimen is FNA. Fresh cells and smears are not acceptable.
Storage and Transportation

Use cold pack for transport, making sure cold pack is not in direct contact with specimen.

CPT Code(s)*
81275, 81276
Medicare MolDX CPT Code(s)*
New York Approved
Level of Service
Turnaround Time

7 days

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.