Molecular Oncology

BCR-ABL qualitative analysis: Performed using reverse transcription polymerase chain reaction (RT-PCR) to detect the presence of the BCR-ABL fusion transcript. Peripheral blood or bone marrow is collected in an EDTA tube, and total RNA is extracted from leukocytes using a standard RNA isolation method. The extracted RNA is then reverse-transcribed into complementary DNA (cDNA) using reverse transcriptase. The cDNA is subjected to PCR amplification using primers specific for the BCR-ABL fusion gene along with an internal control gene to ensure the quality of the reaction. The PCR products are then analyzed by agarose gel electrophoresis, where the presence of a band corresponding to the expected size of the BCR-ABL transcript indicates a positive result. This qualitative test is primarily used for the initial detection of the BCR-ABL fusion gene, which is associated with conditions such as chronic myeloid leukemia (CML) and Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ ALL).

BCR-ABL quantitative test: A specialized molecular diagnostic tool used to detect and measure the presence of the BCR-ABL fusion gene, also known as the Philadelphia chromosome. This genetic abnormality results from a translocation between chromosomes 9 and 22, producing an abnormal tyrosine kinase protein that drives uncontrolled cell growth. The test is performed using real-time polymerase chain reaction (RT-PCR), which quantifies the level of BCR-ABL transcripts in a blood sample. Clinically, it is vital for diagnosing Chronic Myeloid Leukemia (CML) and certain cases of Acute Lymphoblastic Leukemia (ALL). Beyond diagnosis, it plays a crucial role in monitoring disease progression and evaluating a patient’s response to targeted therapies such as tyrosine kinase inhibitors. Regular testing helps physicians adjust treatment plans and detect early signs of resistance or relapse. Accurate results require accredited laboratories and specialist interpretation to guide effective patient management.