Gastrointestinal Stromal Tumors (GISTs), PDGFRA Mutation Analysis

Casandra

Casandra Test Code LC27870Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 510860CPT Codes 81314, 88381

Gastrointestinal Stromal Tumors (GISTs), PDGFRA Mutation Analysis

Also known as: Tyrosine Kinase Inhibitor (TKI, Imatinib) Responsiveness

Clinical Use

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Use

The platelet-derived growth factor receptor alpha (PDGFRA) gene encodes a cell surface tyrosine kinase receptor for members of the platelet-derived growth factor family. PDGFRA and c-KIT have approximately 35% homology. They both belong to the PDGFRA subfamily of receptor tyrosine kinases, which are involved in the regulation of cell growth, proliferation, adhesion, migration, differentiation, and apoptosis. Recently, the kinase inhibitor Avapritinib (AYVAKIT™) was approved for the treatment of adults with unresectable or metastatic gastrointestinal stromal tumor (GIST) harboring a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 mutation, including PDGFRA D842V mutations.

Special Instructions

Not provided.

Limitations

Genomic DNA is purified from the specimen provided. Exons 10, 12, 14, and 18 of PDGFRA gene coding are subjected to PCR amplification and bidirectional sequencing in duplicate to identify sequence variations. This assay has a sensitivity to detect approximately 10% of cells containing the PDGFRA mutations in a background of nonmutant cells. This assay will not detect the mutation below the sensitivity of this assay. This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary.

Test Details