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GNA11 Mutational Analysis

Indication

The GNA11 or guanine nucleotide-binding protein subunit alpha-11, is located on the short arm of chromosome 19 at position 13 (19p13.3), and encodes for the alpha subunit of a heterotrimeric G protein involved in intracellular signaling and signal transduction. The alpha subunit acts as a molecular switch to activate and deactivate intracellular signaling. Mutations of the alpha subunit cause constitutive intracellular signaling, may up-regulate the MAP kinase pathway, and can lead to uncontrolled cell proliferation and cancer.

Mutations in GNA11 have been previously described in <10% of blue nevi, ~30% of uveal melanomas and ~60% of uveal melanoma metastases. A vast majority of reported mutations involve glutamine in position 209 (Q209) of exon 5. MDL has developed sequencing-based testing to assess for mutations in codon 209 of GNA11 to be used in the clinical work-up of patients with melanoma. Characterizing mutations of GNA11 may be useful for prognosis and selection of patients for targeted therapeutic approaches.

 

Methodology

This assay is available as PCR-based DNA sequencing (Sanger or next generation sequencing (NGS)) for codon 209 of the GNA11 gene.

 

Test Parameters

The assay is designed to detect mutations in codon 209 of GNA11. The lower limit of sensitivity of detection is approximately one mutated cell per five (Sanger) to ten (NGS) total cells within the sample (10-20%).

 

Turnaround Time

10 days

 

Sample Requirements

Formalin-fixed, paraffin embedded tissue blocks or 10 unstained slides containing adequate amounts of tumor to be analyzed (see above sensitivity), with areas to be tested clearly indicated on the slides/block. Comparison of normal and tumor, or several different areas of tumor can be done, for an additional charge. Please provide a copy of the corresponding pathology report.

 

CPT Codes

81479

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