What is a BCR-ABL1 Genetic Test?
A BCR-ABL1 Genetic Test detects a specific genetic abnormality called the BCR-ABL1 fusion gene. This abnormal gene is created when parts of chromosomes 9 and 22 exchange genetic material, producing what is commonly known as the Philadelphia chromosome. The BCR-ABL1 fusion gene produces an abnormal protein called a tyrosine kinase, which can cause white blood cells to grow and divide uncontrollably.
The test is most commonly used to help diagnose and monitor Chronic Myeloid Leukemia (CML). It may also be used in some cases of Acute Lymphoblastic Leukemia (ALL) and other blood cancers. A BCR-ABL1 Genetic Test can be performed using techniques such as Polymerase Chain Reaction (PCR), Fluorescence In Situ Hybridization (FISH), or chromosome analysis. Quantitative PCR (qPCR) can measure the amount of BCR-ABL1 genetic material present, making it particularly useful for monitoring how well treatment is working.
How is the Test Performed?
Preparation
- Fasting is not required unless you are having a bone marrow test; then you might have to fast for a few hours.
- Inform your healthcare provider about your medical history and current medications.
- Tell your healthcare provider if you are receiving treatment for leukemia.
- Follow any additional instructions provided before specimen collection.
Collection
- For a blood test, your healthcare professional will collect a blood sample from the vein in your arm using a small needle.
- For a bone marrow test, a healthcare professional typically collects a bone marrow sample from the hip bone using a specialized needle.
Lab Analysis
The collected sample is analyzed using molecular and cytogenetic techniques to detect the BCR-ABL1 fusion gene. Quantitative PCR may be used to measure the amount of BCR-ABL1 transcript in the blood or bone marrow. The results are interpreted alongside blood counts, bone marrow findings, symptoms, and other diagnostic tests to help diagnose leukemia and monitor response to treatment.
What are the symptoms that prompt this test?
A BCR-ABL1 Genetic Test may be recommended when symptoms, blood test abnormalities, or other findings suggest a blood cancer such as chronic myeloid leukemia (CML). It may also be used after diagnosis to monitor the response to treatment.
Symptoms That May Prompt This Test
Your healthcare provider may recommend a BCR-ABL1 Genetic Test if you experience:
- Persistent fatigue or weakness
- Unexplained weight loss
- Fever
- Night sweats
- Frequent infections
- Easy bruising or bleeding
- Pale skin
- Bone or joint pain
- Abdominal fullness or discomfort due to an enlarged spleen
- Unexplained changes in blood cell counts
These symptoms are not specific to BCR-ABL1 abnormalities and may occur with several other medical conditions.
Conditions That May Require This Test
A BCR-ABL1 Genetic Test may also be performed if your healthcare provider suspects or is monitoring:
- Chronic Myeloid Leukemia (CML)
- Philadelphia chromosome-positive Acute Lymphoblastic Leukemia (Ph+ ALL)
- Other BCR-ABL1-positive blood cancers
- Response to tyrosine kinase inhibitor (TKI) treatment
- Possible disease relapse
- Minimal residual disease after treatment
What are Normal Ranges for This Test?
The BCR-ABL1 genetic normal range depends on the testing method and the reason for testing.
Results may generally be reported as:
Not Detected / Negative: No BCR-ABL1 fusion gene or transcript was detected in the sample.
Detected / Positive: BCR-ABL1 was detected, which may support a diagnosis of a BCR-ABL1-positive blood cancer.
Quantitative Result: The amount of BCR-ABL1 is reported as a percentage or ratio and may be used to monitor treatment response over time.
For patients being monitored for CML, molecular response is often assessed using the International Scale (IS). A deeper molecular response is associated with progressively lower BCR-ABL1 transcript levels.
“The reference ranges vary depending on the laboratory and the methodology used. Individuals must consult their healthcare provider for correct interpretation of the results.”
What Happens if Test Results Show Abnormal Findings?
Abnormal BCR-ABL1 Genetic Test results indicate that the BCR-ABL1 fusion gene or transcript has been detected.
Positive BCR-ABL1 Result
A positive result may be associated with:
- Chronic Myeloid Leukemia (CML)
- Philadelphia chromosome-positive Acute Lymphoblastic Leukemia (Ph+ ALL)
- Other rare BCR-ABL1-positive leukemias
A positive result is interpreted alongside blood counts, bone marrow findings, clinical symptoms, and other laboratory investigations.
Increased BCR-ABL1 Levels During Monitoring
In a patient already receiving treatment for CML, an increase in BCR-ABL1 levels may indicate:
- Inadequate treatment response
- Loss of a previous molecular response
- Disease progression
- Possible development of resistance to treatment
Your healthcare provider may repeat the test and investigate potential causes, including treatment adherence or changes in the leukemia cells.
Low or Undetectable BCR-ABL1 Levels
A low or undetectable BCR-ABL1 level during treatment generally indicates a good molecular response. However, continued monitoring is usually required because small amounts of leukemia cells may remain below the test’s detection limit.
Depending on the results, your healthcare provider may recommend additional investigations such as:
- Complete Blood Count (CBC)
- Bone Marrow Tests
- Cytogenetic Testing
- Fluorescence In Situ Hybridization (FISH)
- Quantitative Real-Time PCR (qPCR)
- Additional molecular testing
Need a BCR-ABL1 Genetic Test? Book your appointment today for reliable molecular testing and expert hematology laboratory support.
