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RAS Mutation Detection in Tumors



To detect activating point mutations in the KRAS and NRAS genes, which are commonly present in leukemias with monocytic differentiation (AML, CMML), and in solid tumors such as melanoma, lung cancer and colorectal carcinoma. Presence of KRAS mutations have been shown to confer resistance to anti-EGFR monoclonal antibodies.


PCR-based DNA sequencing; this assay also available on Next Gen Sequencing platforms (CMS46 and CMS53).

Test Parameters

The presence of mutations in codons 12 and 13 as well as codon 61 of NRAS and KRAS are assessed in four separate PCR-DNA sequencing reactions. 


The sensitivity of detection is approximately one mutated cell per five total cells in sample (20%).

Turnaround Time

10-14 working days

Sample Requirements

  • 10-30 ml peripheral blood in lavender top (EDTA) tube, sent on wet ice

  • 2-3 ml bone marrow aspirate in EDTA, sent on wet ice

  • 20 µg of purified DNA, sent on dry ice

Formalin-fixed, paraffin embedded tissue blocks containing adequate amounts of tumor to be analyzed (See Sensitivity.)

Please provide a copy of the corresponding pathology report.

CPT Codes

81275, 81403, 81404

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.

© 2014 The University of Texas MD Anderson Cancer Center