KIT D816, Mutation Analysis (Mastocytosis)

Test Code
91772

CPT Codes
81273<br /> **This test is not available for New York patient testing**

Preferred Specimen
5 mL whole blood collected in an EDTA (lavender-top) tube

Minimum Volume
2 mL whole blood • 0.5 mL bone marrow • 6 slides

Other Acceptable Specimens
Whole blood collected in: sodium heparin (green-top), or acid citrate dextrose ACD-B (yellow-top) tube • 2 mL bone marrow collected in an EDTA (lavender-top) tube • Formalin-fixed, paraffin-embedded tissue block • 10 slides submitted in a slide holder

Transport Temperature
Room temperature

Specimen Stability
Whole blood and bone marrow
Room temperature: 7 days
Refrigerated: 7 days
Frozen: Unacceptable

Tissue block and slides
Room temperature: Indefinitely
Refrigerated: Indefinitely
Frozen: Unacceptable

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Frozen specimens

Methodology
DNA Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Daily; Report available: 5 days

Reference Range
Not detected

Clinical Significance
Point mutation of the KIT oncogene at codon 816 (D816V) is seen in >90% of systemic mastocytosis (SM) cases. The presence of KIT D816V mutation is one of the minor criteria for diagnosis of SM and mutation testing can assist in diagnosis, particularly in limited specimens. KIT D816 mutations, including D816V, D816H and D816Y, are also the most common KIT mutations seen in the core-binding factor acute myeloid leukemia (AML). In both t(8;21) and inv(16)/t(16;16) AML, cases with KIT D816 mutation are associated with worse outcomes than unmutated cases.
This PCR-based DNA pyrosequencing assay sensitively detects the KIT D816V mutation down to 2%. If KIT mutation testing of gastrointestinal stromal tumor (GIST) or melanoma is needed, test code 19961 should be used instead, which tests for exons 8, 9, 11, 13 and 17 of the KIT gene by Sanger sequencing.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153



The CPT Codes provided in this document 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 payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.