Fluorescence in situ hybridization (FISH) for inv(16) is a diagnostic test that is primarily used in the evaluation of acute myeloid leukemia (AML). AML is a type of cancer that affects the myeloid cells in the bone marrow. Inv(16) stands for inversion of chromosome 16, which is a specific chromosomal abnormality often associated with a subtype of AML known as acute myelomonocytic leukemia with eosinophilia (AML M4Eo).
In inv(16), a portion of chromosome 16 is inverted, such that genes that were previously in separate regions are now closer together. Specifically, this inversion brings the CBFB gene in close proximity to the MYH11 gene, resulting in a fusion gene. This fusion gene is believed to contribute to the development of AML.
The FISH test uses fluorescent probes that specifically bind to the regions of interest on chromosome 16. By visualizing these probes under a fluorescence microscope, it is possible to see whether the inversion is present.
Inv(16) is a chromosomal abnormality that involves the inversion of a portion of chromosome 16. This brings the CBFB and MYH11 genes closer together, forming a fusion gene. This fusion gene is associated with a subtype of AML known as AML M4Eo.
Identifying the presence of the inv(16) abnormality is important for diagnosing AML, classifying its subtype, and guiding treatment decisions. Some treatments may be more effective for AML with specific chromosomal abnormalities.
A blood or bone marrow sample is taken from the patient. This sample is then treated with fluorescent probes that specifically bind to regions on chromosome 16. Under a fluorescence microscope, the chromosomes can be visualized and the presence of inv(16) can be determined.
Individuals who have been diagnosed with AML, especially those who have characteristics suggestive of the AML M4Eo subtype, should undergo this test. Additionally, it may be performed for patients with unexplained blood abnormalities or symptoms suggestive of leukemia.
A positive result indicates the presence of inv(16) and suggests that the patient’s AML may belong to the AML M4Eo subtype. This information is critical for treatment planning and prognosis.
Yes, FISH is just one of many tests that can be done to diagnose and monitor AML. Others might include complete blood counts, bone marrow biopsy, cytogenetic analysis, and additional molecular testing.
No special preparation is needed. However, it’s good to follow any instructions provided by your healthcare professional.
Yes, the presence of inv(16) can influence the choice of chemotherapy regimens and is generally associated with a favorable response to certain treatments.
As the test often requires a bone marrow or blood sample, there is a small risk of bleeding, infection, or bruising at the site of the sample collection.
If the test is negative for inv(16), it means that this particular chromosomal abnormality is not present. However, AML is a heterogeneous disease with various genetic abnormalities; your healthcare provider might recommend additional testing.
The results of the FISH test for inv(16) should be interpreted in the context of the clinical picture and other laboratory findings. It is one piece of information that contributes to the diagnosis, classification, and management of AML.
Research is ongoing into the specific molecular mechanisms by which the inv(16) abnormality contributes to the development of AML. Additionally, studies are being conducted to develop targeted therapies that can specifically inhibit the activity of the fusion gene created by inv(16).
Monitoring the presence or absence of inv(16) during and after treatment can provide information on the effectiveness of therapy and give early warning of relapse.
Inv(16) is generally not inherited but acquired during a person’s lifetime. It is a somatic mutation, meaning it occurs in certain cells and is not present in the germ cells (sperm or eggs).
Yes, many organizations offer support groups, education, and resources for patients diagnosed with AML. It’s often helpful to talk with other patients and families who have gone through similar experiences.
FISH for inv(16) is an essential diagnostic tool in the management of AML, particularly the AML M4Eo subtype. This test contributes to a better understanding of the disease's biology, which is critical for personalized treatment planning. If you or a loved one is diagnosed with AML, make sure to discuss with your healthcare team how this and other genetic tests can be used to optimize the treatment strategy.