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HelpTest ID KIT9 KIT Exon 9, Mutation Analysis
Useful For
Diagnosis and management of patients with gastrointestinal stromal tumors or other related tumors
Identification of a mutation in exon 9 of the KIT gene
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SLIRV | Slide Review in MG | No, (Bill Only) | Yes |
Testing Algorithm
This test is performed in conjunction with SLIRV / Slide Review in MG. Additional testing may be performed after review by pathologist. Upon approval from the requesting clinician, 70012 / Pathology Consultation may be added, if determined to be appropriate.
See Gastrointestinal Stromal Tumor (GIST) Testing Algorithm in Special Instructions.
Special Instructions
Method Name
Polymerase Chain Reaction (PCR) and Sequencing
Reporting Name
KIT exon 9, Mutation AnalysisSpecimen Type
VariesA pathology/diagnostic report including a brief history is required. If available, include KIT Immunostain results.
Specimen Type:
Preferred: Formalin-fixed, paraffin-embedded (FFPE) tissue block with a minimum of 60% tumor cell population
Acceptable: Unstained slides with a minimum of 60% tumor population; slides may be stained and/or scraped
Container/Tube: Surgical Pathology Packaging Kit (Supply T554) requested, but not required
Collection Instructions:
1. Process all specimens into FFPE blocks prior to submission.
2. If submitting slides, a minimum of ten, 4- to 5-micron thick, unstained slides are required.
1. A quality specimen is essential for evaluation. Submit only tissue containing tumor cells; minimal tissue is required for evaluation.
2. Special stains performed outside Mayo Medical Laboratories and included with the case may be repeated and charged at the reviewing pathologist's discretion. Testing requested by referring physician may not be performed if deemed unnecessary by Mayo Clinic pathologist.
Forms: If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
Pathology Test Request Form (T246) (http://www.mayomedicallaboratories.com/it-mmfiles/pathology-request-form.pdf)
Oncology Test Request Form (T729) (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Frozen | ||
| Refrigerated | ||
Clinical Information
Several tumors can harbor KIT mutations, including gastrointestinal stromal tumors, mast cell disease, melanoma, seminoma, acute myeloid leukemia, myeloproliferative neoplasms, and lymphomas. The frequency and type of mutations vary among these tumors and portent distinct clinical implications. The ordering physician is responsible for the diagnosis and management of disease and decisions based on the data provided.
Reference Values
An interpretative report will be provided.
Cautions
Reliable results are dependent on adequate specimen collection and processing. This test has been validated on formalin-fixed, paraffin-embedded tissues; other types of fixatives are discouraged. Improper treatment of tissues, such as decalcification, may cause PCR failure. False-negative results may occur in heterozygous tumor specimens when tumor cells comprise <60% of the cell population. Tumor cells are routinely enriched by macrodissection to avoid false-negative results.
Clinical diagnosis and therapy should not be based solely on this assay. The results should be considered in conjunction with clinical information, histologic evaluation, and additional diagnostic tests.
This test is unable to distinguish between a somatic and a germline KIT (or PDGFRA) mutation. Germline KIT (or PDGFRA) mutations are rare and their clinical relevance has been described in more detail in Clinical References 1 and 2. Testing of a peripheral blood specimen from this individual would be required to distinguish a germline from a somatic mutation. This test is not currently offered at Mayo Clinic.
For KIT Asp816Val mutation analysis in mast cell disease, refer to KITAS / KIT Asp816Val Mutation Analysis, Qualitative PCR.
Day(s) Performed
Monday through Friday; Varies
Report Available
14 daysPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
81272-KIT (v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog) (eg, gastrointestinal stromal tumor [GIST], acute myeloid leukemia, melanoma), gene analysis, targeted sequence analysis (eg, exons 8, 11, 13, 17, 18)
88381-Microdissection, manual