What are other Names for this Test? (Equivalent Terms)
- CD117 Mutation Analysis Test
- Piebald Trait Protein Mutation Analysis Test
- v-kit Hardy-Zuckerman 4 Feline Sarcoma Viral Oncogene Homolog Mutation Analysis Test
What is KIT Mutation Analysis Test? (Background Information)
- KIT mutation refers to an alteration in the KIT gene, which is associated with immune, gastrointestinal, skin, eye, and hair cancers and other disorders
- The KIT gene gives instructions for the KIT protein. The KIT protein is a type of receptor tyrosine kinase (RTK). RTKs reside on the surfaces of certain cells, where they act as antennas that receive signals from outside the cell and transmit them inside the cell
- The KIT protein is found primarily on the membranes of developing blood cells, reproductive cells, intestinal cells, and certain skin cells (called melanocytes)
- The signal that the KIT protein recognizes and binds is a chemical called stem cell factor. Once bound with stem cell factor, KIT launches a chain of events inside the cell that leads to the growth and division of the cell. KIT is necessary for the survival and movement of cells, and for maintaining the balance of cell populations
- Alterations in the KIT gene may result in a defective KIT protein that may activate itself independently of stem cell factor. The defective KIT is overactive as a result of its no longer needing stem cell factor to bind in order to activate
- Alterations in the KIT gene that affect KIT protein function may interfere with normal growth and division of cells, causing cancer
- The KIT Mutation Analysis Test is a genetic test that detects abnormalities in the KIT gene. It is used to diagnose cancer. It also aids in the treatment of cancers by guiding selection of therapeutic drugs, including disqualifying certain drugs from use
The molecular testing, in general, can be performed using a variety of methods. Some of these methods include:
- In situ hybridization techniques, such as fluorescence in situ hybridization (FISH)
- Immunohistochemistry (IHC)
- Next-generation sequencing (NGS)
- Polymerase chain reaction (PCR)
- Comparative genomic hybridization (CGH)
- Karyotyping including spectral karyotyping
- mRNA analysis
- Tissue microarrays (TMAs)
- Southern blot test
- Northern blot test
- Western blot test
- Eastern blot test
The methodology used for the test may vary from one laboratory to another.
Note: Molecular testing has limitations due to the molecular method and genetic mutational abnormalities being tested. This can affect the results on a case-by-case basis. Consultation with your healthcare provider will help in determining the right test and right molecular method, based on individual circumstances.
What are the Clinical Indications for performing the KIT Mutation Analysis Test?
The clinical indications for performing the KIT Mutation Analysis Test may include:
- Abdominal discomfort or pain
- Blood in the stools or vomit
- Anemia (low level of red blood cells)
- A painless lump in the abdomen
- Fever, night sweats
- Unexplained weight loss
- Bone pain
- Shortness of breath
- Pale skin
- Frequent infections
- Easy bruising
- Unusual bleeding, such as frequent nosebleeds and bleeding from the gums
In general, the molecular genetic testing is undertaken in the following situations:
- To assist (and in some cases, confirm) the initial diagnosis
- If there is a family history of the medical disorder/condition
- To distinguish other conditions that have similar features (signs and symptoms)
- To help in determining treatment options
- To confirm recurrence of the tumor: Tumor recurrence can either be at the original tumor site, or at a distant location (away from the initial site)
How is the Specimen Collected for KIT Mutation Analysis Blood Test?
Following is the specimen collection process for KIT Mutation Analysis Blood Test:
The specimen sample requirements may vary from lab to lab. Hence, it is important to contact the testing lab for exact specimen requirements, before initiating the testing process.
- Sample on which the test is performed may include:
- Peripheral blood in individuals showing signs and symptoms suspected of TTT
- In case of expectant mothers, prenatal testing through amniotic fluid and chorionic villi sampling
- Fresh tumor tissue during biopsy: In some cases, the testing can be performed on tumor tissue also
- Formalin-fixed paraffin-embedded solid tumor tissue (FFPE tumor tissue), often referred to as paraffin block of the tumor
- Unstained tissue slides
- Process of obtaining the sample: As outlined by the laboratory testing facility
- Preparation required: As outlined by the laboratory testing facility
- In some cases, a different source of specimen (such as peripheral blood, bone marrow biopsy specimen, or other body fluids) may be acceptable to the laboratory performing the test
- Occasionally, additional samples may be required to either repeat the test or to perform follow-up testing
- Depending on the location of testing, it may take up to 2 weeks’ turnaround time, to obtain the test results
- Many hospitals preserve the paraffin blocks for at least 7 years. In general, older paraffin blocks (over 5 years) may affect the detection of specific mutations, due to degradation of the tumor specimen over time
Cost of KIT Mutation Analysis Blood Test:
- The cost of the test procedure depends on a variety of factors, such as the type of your health insurance, annual deductibles, co-pay requirements, out-of-network and in-network of your healthcare providers and healthcare facilities
- In many cases, an estimate may be provided before the test is conducted. The final amount may depend upon the findings during the test procedure and post-operative care that is necessary (if any)
What is the Significance of the KIT Mutation Analysis Blood Test Result?
A mutation in the KIT gene indicates a positive result for the KIT Mutation Analysis Blood Test. This may point to a diagnosis of:
- Acute myeloid leukemia (AML)
- Gastrointestinal stromal tumor (GIST)
- Sinonasal natural killer/T-cell lymphoma (NKTCL)
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- KIT mutation most notably occurs in a location of the chromosome called 4q12 i.e., the long arm (q) of chromosome 4 in position 12
- Many laboratories may not have the capability to perform this test. Only highly-specialized labs with advanced facilities and testing procedures may perform this test
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
What are some Useful Resources for Additional Information?
The following DoveMed website links are useful resources for additional information:
Please visit our Laboratory Procedures Center for more physician-approved health information:
References and Information Sources used for the Article:
https://ghr.nlm.nih.gov/primer/testing/genetictesting (accessed on 05/10/2017)
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5806a1.htm (accessed on 05/10/2017)
http://www.nature.com/gim/journal/v10/n5/full/gim200852a.html (accessed on 05/10/2017)
http://pediatrics.aappublications.org/content/106/6/1494 (accessed on 05/10/2017)
Gastrointestinal stromal tumours (GISTs) - Understanding cancer - Macmillan Cancer Support. (n.d.). Retrieved from http://www.macmillan.org.uk/information-and-support/soft-tissue-sarcomas/gastrointestinal-stromal-tumours
KIT gene - Genetics Home Reference. (n.d.). Retrieved from https://ghr.nlm.nih.gov/gene/KIT#location
Mayo Clinic. (2015, September 12). Acute myelogenous leukemia (AML) Symptoms. Retrieved from http://www.mayoclinic.org/diseases-conditions/acute-myelogenous-leukemia/basics/symptoms/con-20043431
Helpful Peer-Reviewed Medical Articles:
Carrano, A. V., et al. Measurement and purification of human chromosomes by flow cytometry and sorting. Proceedings of the National Academy of Sciences 76, 1382–1384 (1979)
Drets, M. E., & Shaw, M. W. Specific banding patterns of human chromosomes. Proceedings of the National Academy of Sciences 68, 2073–2077 (1971)
Druker, B. J. Perspectives on the development of a molecularly targeted agent. Cancer Cell 1, 31–36 (2002)
Parra, I., & Windle, B. High resolution visual mapping of stretched DNA by fluorescent hybridization. Nature Genetics 5, 17–21 (1993) doi:10.1038/ng0993-17
Pinkel, D., et al. High resolution analysis of DNA copy number variation using comparative genomic hybridization to microarrays. Nature Genetics 20, 207–211 (1998) doi:10.1038/2524
Speicher, M. R., et al. Karyotyping human chromosomes by combinatorial multi-fluor FISH. Nature Genetics 12, 368–375 (1996) doi:10.1038/ng0496-368
Pollard, J. A., Alonzo, T. A., Gerbing, R. B., Ho, P. A., Zeng, R., Ravindranath, Y., ... & Weinstein, H. J. (2010). Prevalence and prognostic significance of KIT mutations in pediatric patients with core binding factor AML enrolled on serial pediatric cooperative trials for de novo AML. Blood, 115(12), 2372-2379.
Janeway, K. A., Kim, S. Y., Lodish, M., Nosé, V., Rustin, P., Gaal, J., ... & Lai, A. H. (2011). Defects in succinate dehydrogenase in gastrointestinal stromal tumors lacking KIT and PDGFRA mutations. Proceedings of the National Academy of Sciences, 108(1), 314-318.
Bodemer, C., Hermine, O., Palmérini, F., Yang, Y., Grandpeix-Guyodo, C., Leventhal, P. S., ... & Launay, J. M. (2010). Pediatric mastocytosis is a clonal disease associated with D 816 V and other activating c-KIT mutations. Journal of Investigative Dermatology, 130(3), 804-815.
Guo, J., Si, L., Kong, Y., Flaherty, K. T., Xu, X., Zhu, Y., ... & Cui, C. (2011). Phase II, open-label, single-arm trial of imatinib mesylate in patients with metastatic melanoma harboring c-Kit mutation or amplification. Journal of Clinical Oncology, 29(21), 2904-2909.
Carvajal, R. D., Antonescu, C. R., Wolchok, J. D., Chapman, P. B., Roman, R. A., Teitcher, J., ... & Pavlick, A. C. (2011). KIT as a therapeutic target in metastatic melanoma. Jama, 305(22), 2327-2334.