What are other Names for this Test? (Equivalent Terms)

• MYD88_HUMAN Mutation Analysis Test
• MYD88D Mutation Analysis Test
• Myeloid Differentiation Primary Response Gene (88) Mutation Analysis Test

What is MYD88 Mutation Analysis Test? (Background Information)

• MYD88 mutation refers to an alteration in the MYD88 gene, which is associated with cancers, such as lymphoma and Waldenström macroglobulinemia (the latter in up to 90% of individuals)
• The MYD88 gene gives instructions for the MYD88 protein. MYD88 helps cells communicate with each other. It relays messages received from outside the cell, to grow and reproduce, to the relevant machinery within the cell that may enact those changes
• MYD88 obtains its messages from proteins found on the cell surface. These proteins are called receptors, because they act as antennas. Receptor proteins that provide signals to MYD88 include interleukin-1 receptor and toll-like receptor
• MYD88 then relays its message to proteins of the NF-kB pathway. The end-result of the NF-kB pathway is growth and division of the cell, release of inflammatory compounds by the cell, and/or self-destruction of the cell
• This system of signal transduction involving MYD88 and its partners is important for the immune response, because it allows immune system cells to respond to pathogens on the outside. Problems with the MYD88 gene may result in an MYD88 protein that is defective
• The possible effects on MYD88 and health include the following:
  • Dysfunctional MYD88: The protein is unable to stimulate the immune system even in the presence of pathogens such as bacteria. This increases the body’s susceptibility to infections that can result in infections that do not resolve
  • Overactive MYD88: The protein stimulates the NF-kB pathway even without being informed by receptor proteins on the cell’s surface. The result of overactive MYD88 is abnormal blood cell formation and uncontrolled growth and division i.e., cancer
• The MYD88 Mutation Analysis Blood Test is a genetic test that detects abnormalities in the MYD88 gene. It is used to diagnose blood cell disorders, such as leukemia, and blood cell deficiencies. The test also aids in the treatment of cancer and blood cell deficiencies 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 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 MYD88 Mutation Analysis Test?

Following are the clinical indications for performing the MYD88 Mutation Analysis Test:

• Fatigue
• Unexplained weight loss
• Enlarged lymph nodes or spleen
• Numbness, weakness or other nervous system problems, pain in the hands or feet, sometimes called peripheral neuropathy
• Abdominal swelling and diarrhea
• Weakness and shortness of breath
• Infections
• Raised pink or flesh-colored lesions on the skin
• Changes in the color of the finger tips when exposed to cold
• Changes in vision, which may include blurry vision or “double” vision
• Unexplained weight loss
• Unexplained fever
• Heavy sweating, especially at night, that may drench one’s nightclothes or sheets on the bed.
• Severe and/or extensive skin itchiness

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 MYD88 Mutation Analysis Test?

Following is the specimen collection process for MYD88 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

Note:

• 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 MYD88 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 MYD88 Mutation Analysis Test Result?

A mutation in the MYD88 gene indicates a positive result for the MYD88 Mutation Analysis Test. This may point to a diagnosis of any of the following:

• Waldenström macroglobulinemia
• Diffuse large B-cell lymphoma (DLBCL)
• Marginal zone lymphoma
• IgM monoclonal gammopathy of undetermined significance (IgM-MGUS)

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:

• MYD88 mutation most notably occurs in a location of the chromosome called 3p22.2 i.e., the short arm (p) of chromosome 3 in position 22.2
• 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.

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/leukemia-and-lymphoma/

Please visit our Laboratory Procedures Center for more physician-approved health information:

http://www.dovemed.com/common-procedures/procedures-laboratory/