GISTAppendix

Note 1: Some gastrointestinal stromal tumors (GIST) have oncogenic mutations of the platelet-derived growth factor receptor alpha (PDGFRA)gene, located on chromosome 4q. This test is a special molecular diagnostic test performed on tumor tissue to identify PDGFRA mutations. Some GISTs that are negative for KIT mutations are positive for PDGFRA mutation.
Note 2: Code the result of the PDGFRA gene test. Another name for PDGFRA is CD140A.
Note 3: See CS Site-Specific Factors 12 and 13 for coding information about KIT gene expression and mutations.

Code	Description
010	PDGFRA gene test positive for mutations
020	PDGFRA gene test negative for mutations; no mutations; normal or wild-type gene
988	Not applicable: Information not collected for this case (If this information is required by your standard setter, use of code 988 may result in an edit error.)
997	Test ordered, results not in chart; results pending
998	Test not done (test not ordered and not performed)
999	Unknown or no information Not documented in patient record

CS Site-Specific Factor 14PDGFRA Gene Mutation