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Test Id : KITVS

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KIT Asp816Val Mutation Analysis, Varies

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing systemic mastocytosis using blood or bone marrow specimens

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Method Name
A short description of the method used to perform the test

Allele-Specific Oligonucleotide Polymerase Chain Reaction (PCR)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

KIT Asp816Val Mutation Analysis, V

Aliases
Lists additional common names for a test, as an aid in searching

C-KIT

D816V

Systemic Mastocytosis Mutation

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Specimen Type
Describes the specimen type validated for testing

Varies

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
MP055 Specimen Type Peripheral blood
Bone marrow
Extracted DNA from blood
Extracted DNA from bone marrow

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA) or yellow top (ACD)

Specimen Volume: 3 mL

Collections Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube. Do not aliquot.

3. Label specimen as blood.

Specimen Stability Information: Ambient (preferred) 7 days/Refrigerate 7 days

 

Specimen Type: Bone marrow

Container/Tube: Lavender top (EDTA) or yellow top (ACD)

Specimen Volume: 2 mL

Collections Instructions:

1. Invert several times to mix bone marrow.

2. Send specimens in original tube. Do not aliquot.

3. Label specimen as bone marrow.

Specimen Stability Information: Ambient (preferred) 7 days/Refrigerate 7 days

 

Specimen Type: Extracted DNA from blood or bone marrow

Container/Tube: 1.5- to 2-mL tube

Specimen Volume: Entire specimen

Collection Instructions:

1. Label specimen as extracted DNA from blood or bone marrow.

2. Provide indication of volume and concentration of DNA.

Specimen Stability Information: Frozen (preferred)/Refrigerated/Ambient

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

1. Hematopathology Patient Information (T676)

2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726)) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

Blood, Bone Marrow: 1 mL

Extracted DNA: 50 mcL at 20 ng/mcL concentration

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Moderately to severely clotted
Bone marrow biopsies
Paraffin-embedded bone marrow clots
Paraffin-embedded tissue
Slides
Paraffin shavings 		Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing systemic mastocytosis using blood or bone marrow specimens

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Systemic mastocytosis is a hematopoietic neoplasm that can be included in the general category of chronic myeloproliferative disorders (CMPD). These neoplasms are characterized by excessive proliferation of one or more myeloid lineages, with cells filling the bone marrow and populating other hematopoietic sites. In systemic mastocytosis, mast cell proliferation is the defining feature, although other myeloid lineages and B cells are frequently part of the neoplastic clone.

 

Function-altering point alterations in KIT, a gene coding for a membrane receptor tyrosine kinase, have been found in myeloid lineage cells in the majority of systemic mastocytosis cases. The most common KIT alteration is an adenine to thymine base substitution (A>T) at nucleotide position 2447, which results in an aspartic acid to valine change in the protein (Asp816Val). Much less frequently, other alterations at this same location are found, and occasional cases with alterations at other locations have also been reported. Variations at codon 816 are believed to alter the protein such that it is in a constitutively activated state. The main downstream effect of KIT activation is cell proliferation.

 

Detection of a variant at codon 816 is included as one of the minor diagnostic criteria for systemic mastocytosis in the World Health Organization classification system for hematopoietic neoplasms and is also of therapeutic relevance, as it confers resistance to imatinib, a drug commonly used to treat CMPD. It is now clear that individual mast cell neoplasms are variable with respect to the number of cell lineages containing the variant; some having positivity only in mast cells and others having positivity in additional myeloid and even lymphoid lineages. The alteration has not been reported in normal tissues.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided indicating the mutation status as positive or negative.

Interpretation
Provides information to assist in interpretation of the test results

The test will be interpreted as positive or negative for KIT Asp816Val.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Some systemic mastocytosis cases may have the variation only in mast cells. Since these cells rarely circulate in blood and are difficult to obtain in significant numbers from bone marrow aspirate specimens, false-negative results may occur if neoplastic cells are present below the sensitivity of the assay (fewer than 0.1% altered alleles).

 

The test is qualitative only. Reliable quantitative results cannot be issued.

Supportive Data

The analytic sensitivity of this test is 0.1% and was determined by the dilution of a cell line containing homozygous KIT alteration. This means that 0.1% or greater of the KIT alleles present in the specimen must contain the alteration to be detected by the assay. The analytic specificity was 100% in assay validation.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Garcia-Montero AC, Jara-Acevedo M, Teodosio C, et al. KIT mutation in mast cells and other bone marrow hematopoietic cell lineages in systemic mast cell disorders: a prospective study of the Spanish Network on Mastocytosis (REMA) in a series of 113 patients. Blood. 2006;108:2366-2372. doi:10.1182/blood-2006-04-015545

2. Valent P, Akin C, Sperr WR, et al. Diagnosis and treatment of systemic mastocytosis: state of the art. Br J Haematol. 2003;122:695-717. doi:10.1046/j.1365-2141.2003.04575.x

3. Jaffe ES, Harris NL, Stein H, et al. Pathology and Genetics. In: WHO Classification of Tumours of the Haematopoietic and Lymphoid Tissues. 2001:291-302. World Health Organization Classification of Tumours. Vol 2

4. Pardanani A. Systemic mastocytosis in adults: 2012 Update on diagnosis, risk stratification, and management. Am J Hematol. 2012;87:402-411. doi: 10.1002/ajh.23134.

5. Munoz-Gonzalez JI, Alvarez-Twose I, Jara-Acevedo M, et al. Frequency and prognostic impact of KIT and other genetic variants in indolent systemic mastocytosis. Blood. 2019; 134(5):456-468. doi:10.1182/blood.2018886507

Method Description
Describes how the test is performed and provides a method-specific reference

This assay detects the KIT alteration responsible for Asp816Val. The technique used is allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) with fragment analysis on a genetic analyzer. DNA is extracted from bone marrow or blood, and PCR is used to amplify across the alteration site in 2 separate tubes; one contains a reverse primer complementary to the unaltered sequence and the other contains a reverse primer complementary to the altered sequence. Each of these is labeled with a fluorescent tag and contains an identical, non-labeled forward primer. Both primer sets amplify a 200 base pair fragment that differs only at the alteration site. The unaltered fragment should be amplified in all samples. Samples negative for KIT Asp816Val will not have an amplified fragment in the altered sequence reaction tube. Positive samples will have amplified fragments in both tubes. The test gives a qualitative (positive or negative) result only, as the end point PCR used is not reliable for quantification.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

4 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Whole blood, bone marrow: 2 weeks; Extracted DNA: 3 Months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

81273

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
KITVS KIT Asp816Val Mutation Analysis, V 55201-8
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
MP055 Specimen Type 31208-2
607982 Interpretation 69047-9
607983 Signing Pathologist 19139-5

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports