KITMutations

Specimen Collection, Storage, and Shipping

Test Information:

This assay detects activating mutations in exons 8, 9, 11, 13, 17, and/or 18 of the KIT gene, such as in gastrointestinal stromal tumors (GISTs), systemic mastocytosis, AML, and acral and mucosal melanomas. Mutations are detected using PCR followed by dideoxynucleotide sequencing. Our Sanger sequencing method can detect up to 20-30% mutation frequency. If the patient does not have a high mutation burden, then this assay may miss a low-level mutation.
AML: exons 8 (1.8%) and 17 (~6%).
GIST: exons 11 (~70%) and 9 (10-15%), less frequent 13 (<2%) and 17 (<2%).

Requisition Code:

cKIT mutation – indicate on requisition which exons (ex 8, ex 9, ex 11, ex 13, ex 17, ex 18, or all) should be tested.
Typically, exons 8 and 17 are analyzed for cases of AML, and exons 11 and 17 for GIST.

CPT Code:

81272; G0452-26 (add 88381 if manual microdissection is needed)

Turn Around Time:

7-10 days

Specimen Requirements:

Fluid

Collect:
Peripheral blood: 2-5 mL in EDTA (purple top) tube
Bone marrow: 2-5 mL in ACD (yellow top) or EDTA (purple top) tube
Storage:
Room temperature
Transport: See Standard Shipping Procedures

Paraffin Block

Decalcified specimens are not accepted.
Collect: Formalin-fixed, paraffin embedded tissues
Storage: Room temperature
Remarks: Submit the paraffin block, 1 H&E with marked location of most abundant tumor (or photocopy of marked H&E) and an approximate % of tumor cells in the area and a copy of the Surgical Pathology report.
Transport: See Standard Shipping Procedures

References:

  1. Maki, R., V. Keedy. Sept 29, 2014. KIT Exon 11 Mutation in GIST. My Cancer Genome. Available at https://www.mycancergenome.org/content/disease/gist/kit/47/ (Accessed 3/5/2019)
  2. Wheeler, S., A. Seegmiller, C. Vnencak-Jones. Sept 9, 2013. KIT in Acute Myeloid Leukemia. My Cancer Genome. Available at https://www.mycancergenome.org/content/disease/acute-myeloid-leukemia/kit/ (Accessed 3/5/2019).