What are other Names for this Test? (Equivalent Terms)
- ASXL1 Gene Sequencing Test
- ASXL1 Gene Mutation Test
- ASXL1 Mutation Test
What is ASXL1 Mutation Analysis Test? (Background Information)
- ASXL1 mutation refers to an alteration in the ASXL1 gene. This condition is associated with cancers of the bone marrow and blood cells including:
- Acute myeloid leukemia (AML; 11% of the cases have mutations)
- Myeloproliferative neoplasms (MPN)
- Myelodysplastic syndromes (MDS; 14% of the cases have mutations)
- Chronic myelomonocytic leukemia (CMM; 45% of the cases have mutations)
- Juvenile myelomonocytic leukemia (JMML; rare cases show mutations)
- ASXL1 is a segment of DNA that helps regulate the process of converting other genes to proteins. Some of the genes that ASXL1 regulates give instructions for proteins associated with cell growth and division
- Because of its important role in regulating the production of proteins linked to cell proliferation, alterations in the ASXL1 gene are associated with abnormal cell growth characteristic of cancer
- Most mutations in the ASXL1 gene occur in a region called exon 13. Genes such as ASXL1, made of DNA, are used to make RNA, which is then used to make proteins. Exons result from the processing of RNA. The term exon refers to the region of DNA or RNA that will eventually be used to form proteins
- The ASXL1 Mutation Analysis Test is a genetic test that detects abnormalities in the ASXL1 gene. It is used to guide the treatment for cancer. The blood test can also aid in the selection for therapeutic drugs for cancer treatment, and help may disqualify certain drugs from being used
The molecular testing, in general, can be performed using a variety of methods. Some of these methods include:
- In situ hybridization technique, 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 ASXL1 Mutation Analysis Test?
Following are the clinical indicators for performing the ASXL1 Gene Mutation Analysis Test include:
- Monitoring cancer therapy
- Assessing treatment options for leukemia and other cancers
In general, the molecular genetic testing is undertaken in the following situations:
- To assist (and in some cases, confirm) the initial diagnosis
- To distinguish other tumors/conditions that have similar histological features, when examined by a pathologist under the microscope
- 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 ASXL1 Mutation Analysis Test?
Following is the specimen collection process for ASXL1 Mutation Analysis 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:
- Fresh tumor tissue during biopsy
- 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 ASXL1 Mutation Analysis 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 ASXL1 Mutation Analysis Test Result?
- A positive value for the ASXL1 Mutation Analysis Test may disqualify certain therapeutic drugs from being used to treat acute myeloid leukemia, myeloproliferative neoplasms, myelodysplastic syndromes, and chronic or juvenile myelomonocytic leukemia
- The presence of a mutation in ASXL1 in combination with cancer is a serious condition. It is associated with:
- Aggressive cancer and poor prognosis
- Short survival
- Elevated International Prognostic Scoring System risk group
- Increased risk of transformation to AML
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:
- Mutations in ASXL1 gene are more prevalent in men, elderly individuals, and those with a history of myelodysplastic syndromes (MDS)
- 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 of 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 link is a useful resource 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)
BloodCenter of Wisconsin. (2016, March). ASXL1 Mutation Analysis.
Martini, F., Nath, J. L., & Bartholomew, E. F. (2012). Fundamentals of anatomy & physiology (9th ed.). San Francisco: Benjamin Cummings.
Quest Diagnostics. (2014, March). Lung Cancer Mutation Panel (EGFR, KRAS, ALK). Retrieved from http://www.questdiagnostics.com/testcenter/testguide.action%3Fdc%3DTS_LungCancerMutation_Panel
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
Xie, M., Lu, C., Wang, J., McLellan, M. D., Johnson, K. J., Wendl, M. C., ... & Ozenberger, B. A. (2014). Age-related mutations associated with clonal hematopoietic expansion and malignancies. Nature medicine, 20(12), 1472-1478.
Shen, W., Szankasi, P., Sederberg, M., Schumacher, J., Frizzell, K., Gee, E. P., ... & Kelley, T. W. (2015). Targeted Detection of Copy Number Variants Using a Myeloid Malignancy Next Generation Sequencing Mutation Panel Allows Comprehensive Genetic Analysis Using a Single Testing Method. Blood, 126(23), 2887-2887.
Chen, T. C., Hou, H. A., Chou, W. C., Tang, J. L., Kuo, Y. Y., Chen, C. Y., ... & Lee, F. Y. (2014). Dynamics of ASXL1 mutation and other associated genetic alterations during disease progression in patients with primary myelodysplastic syndrome. Blood cancer journal, 4(1), e177.
Vannucchi, A. M., Lasho, T. L., Guglielmelli, P., Biamonte, F., Pardanani, A., Pereira, A., ... & Ketterling, R. P. (2013). Mutations and prognosis in primary myelofibrosis. Leukemia, 27(9), 1861-1869.
Patnaik, M. M., Padron, E., LaBorde, R. R., Lasho, T. L., Finke, C. M., Hanson, C. A., ... & Pardanani, A. (2013). Mayo prognostic model for WHO-defined chronic myelomonocytic leukemia: ASXL1 and spliceosome component mutations and outcomes. Leukemia, 27(7), 1504-1510.
Schnittger, S., Eder, C., Jeromin, S., Alpermann, T., Fasan, A., Grossmann, V., ... & Kreuzer, K. A. (2013). ASXL1 exon 12 mutations are frequent in AML with intermediate risk karyotype and are independently associated with an adverse outcome. Leukemia, 27(1), 82-91.
Itzykson, R., Kosmider, O., Renneville, A., Morabito, M., Preudhomme, C., Berthon, C., ... & Rameau, P. (2013). Clonal architecture of chronic myelomonocytic leukemias. Blood, 121(12), 2186-2198.
Patnaik, M. M., Itzykson, R., Lasho, T. L., Kosmider, O., Finke, C. M., Hanson, C. A., ... & Solary, E. (2014). ASXL1 and SETBP1 mutations and their prognostic contribution in chronic myelomonocytic leukemia: a two-center study of 466 patients. Leukemia, 28(11), 2206-2212.