PDGFRA Mutation for GIST

Order Code:                  PDGF

Fee Code:                    NA064 (CPT 81314, G0452-26)

Effective June 4, 2024, KIT Mutation – Exons 9, 11, 13, 17 and PDGFRA Mutation for GIST will be discontinued and replaced by new assay KIT and PDGFRA Mutation for GIST. The discontinued tests each employed Sanger sequencing of KIT exons 9, 11, 13 and 17; and PDGFRA exons 12 and 18. KIT mutations occur in approximately 80% of GISTs and approximately 30% of KIT wild-type GISTs harbor PDGFRA mutations. Testing for KIT and PDGFRA mutations can aid in the diagnosis of GIST and can also predict response to specific tyrosine kinase inhibitor therapies.

 

The new assay employs next-generation sequencing (NGS). The new test has a lower limit of detection – 10% mutation-bearing cells compared to 30%. The new test also covers KIT exon 8 and PDGFRA exon 14, in addition to the exons cover by prior testing – KIT exons 9, 11, 13, 17; PDGFRA exon 12, 18. Finally, both genes are sequenced simultaneously, negating the need to order two Sanger sequencing tests.

 

To detect KIT and PDGFRA mutations as well as other mutations that occur in GISTs – such as BRAF, HRAS, NRAS – the Solid Tumor NGS Panel (order code NGSST) is an alternative test that could be used.