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NRAS Exons 2-4 Mutation by Next Generation Sequencing (NGS) (8000101248)
Test Mnemonic:

NRAS Exons 2-4 Mutation NGS

Specimen Requirements:

Tumor sample/sample with tumor cells


Formalin fixed (10 percent neutral buffered formalin) and paraffin embedded tissue sections (prepared in Surgical Pathology).  Transport 5 unstained 5-10 micron slides (Minimum is 3 slides depending on the size of the tumor) with a matching HE slide marked tumor area.

Tumor cell smear/cell block (prepared in Cytopathology) or blood samples may be used when there are enough tumor cells in the sample.


Labeled microscope slides with tumor cells

Minimum Volume:

Must have 20% tumor cells in the marked area for mutation analysis


Protect specimens from excessive heat. Ship in cooled container during summer months. Transport at room temperature or refrigerated

Specimen Preparation:

Slides are prepared by Surgical Pathology or Cytopathology

Causes for Rejection:

Specimens with less than 20% tumor cells. Incomplete and/or incorrect specimen identification.

Reference Range:

Not Detected

Turnaround Time:

10 days


Next Generation Sequencing


Molecular Diagnostics Laboratory


NRAS, NRAS Mutation

Clinical Indication:

May serve as a companion predicative marker for anti-MEK treatment; May serve as companion predictive marker for anti-EGFR treatment; May be used for tumor prognosis.

CPT 4 Code:




Oncogenic NRAS mutations have been linked to resistance to anti-EGFR therapies. Test results can predict response to anti-EGFR and MAPK pathway therapies in a variety of malignancies including colorectal cancer and melanoma.

Limit of detection: 10% mutant alleles (20% tumor cells).

Genomic DNA is isolated from macro-dissected tumor tissue and amplified for segments of the NRAS gene covering codons 12, 13, and 61. Mutation status for these three codons is determined by pyrosequencing. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

This test was developed and its performance characteristics were determined by UTMB Pathology Molecular Diagnostics Laboratory. It has not been cleared or approved by the U. S. Food and Drug Administration (FDA). The FDA has determined that such clearance or approval is not necessary. This test is used for clinical purposes. It should not be regarded as investigational or for research. This laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88) as qualified to perform high complexity clinical laboratory testing.


When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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