• Test Code:
    4206
  • Department:
    Hematological Malignancies
  • Test Synonyms:
    KIT (cKIT) Mutation Screening for Acute Myelogenous Leukemia (exons 8 & 17)
  • CPT Code(s):
    81404
Background:

Oncogenic KIT gene mutations are present in a subset of acute myelogenous leukemias with inv16 or a translocation involving AML-1 (e.g. t[8;21]).1,2 The mutations occur most commonly in exons 17 and 8 of the KIT gene, but the relative frequency varies somewhat among different studies. Cases with exon 17 mutations have a significantly worse prognosis. 

Methodology:

This test is performed by PCR-based Next Generation Sequencing of DNA extracted from fresh tissue including peripheral blood and bone marrow.  Hotspot exons 8 and 17 in CKIT are sequenced using massively parallel sequencing (next-generation sequencing) with a combination of multiplexed PCR (customized QIAseq Targeted DNA panel) and sequencing on an Illumina platform.  An in-house bioinformatics analysis pipeline has been used that employs multiple established variant calling tools (FreeBayes, MuTect2 and Scalpel) and variant annotation tools.  The genomic variants have been interpreted in accordance with the 2017 guideline recommendations by AMP/ASCO/CAP (PMID: 27993330).  The assay is validated in accordance with the AMP guidelines (PMID: 28341590).

The lower detection limit of this assay is 1-2% VAF depending on read quality and quantity.

Specimen Requirements:

Blood or bone marrow: Yellow (ACD) or purple (EDTA) tube (unspun)

    • Adult: 5mL
    • Child: 5mL
    • Infant: 2-3mL 

Paraffin blocks or unstained slides:

  • 10 slides at 4-5 microns

DNA: 1µg at a minimum of 50-100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information.

Test Performed (Days):

Weekly

Turn Around Time:

7-10 days

Shipment Sensitivity Requirements:

  • Package and ship specimen to remain cool during transit, but not frozen, unless shipping frozen pellets.
  • Please the use the cold pack provided in the KDL shipping kit.
  • Ship the specimen via overnight express, using the FedEx priority overnight label provided. 
  • Contact Client Services for shipping materials and procedures at (855) 535-1522.

References:

  1. Cairoli R, Beghini A, Grillo G, Nadali G, Elice F, Ripamonti CB, Colapietro P, Nichelatti M, Pezzetti L, Lunghi M, Cuneo A, Viola A, Ferrara F, Lazzarino M, Rodeghiero F, Pizzolo G, Larizza L, Morra E   Prognostic impact of c-KIT mutations in core binding factor leukemias: an Italian retrospective study. Blood. 2006 May 1;107(9):3463-8.
  2. Paschka P, Marcucci G, Ruppert AS, Mrozek K, Chen H, Kittles RA, Vukosavljevic T, Perrotti D, Vardiman JW, Carroll AJ, Kolitz JE, Larson RA, Bloomfield CD; Cancer and Leukemia Group B. Adverse prognostic significance of KIT mutations in adult acute myeloid leukemia with inv(16) and t(8;21): a Cancer and Leukemia Group B Study. J Clin Oncol. 2006 Aug 20;24(24):3904-11.

Additional Info: