BCR-ABL (CML) Quantitative

BCR‑ABL quantitative is a laboratory qPCR test that measures the amount of BCR‑ABL fusion gene transcripts in blood or bone marrow. Results are reported on the International Scale as a percentage to monitor chronic myeloid leukemia treatment response, detect minimal residual disease, and guide therapy decisions. Falling transcript levels indicate effective therapy; rising levels suggest relapse or resistance.

Yes. Chronic myeloid leukemia (CML) is defined by the BCR‑ABL fusion (Philadelphia chromosome) in the vast majority of cases—over 90–95%. This t(9;22) translocation creates a constitutively active BCR‑ABL tyrosine kinase, driving disease and serving as a diagnostic marker and therapeutic target. Detection guides treatment with tyrosine‑kinase inhibitors and monitoring response.

BCR‑ABL1 positive means a chromosomal fusion (the Philadelphia chromosome) producing the BCR‑ABL1 oncogene. Its abnormal tyrosine‑kinase activity drives uncontrolled white‑blood‑cell growth and is diagnostic for conditions like chronic myeloid leukemia and some acute lymphoblastic leukemias. Detection (by PCR or FISH) confirms diagnosis, guides tyrosine‑kinase inhibitor therapy, and enables monitoring of treatment response and minimal residual disease.

Normal BCR‑ABL1 is essentially undetectable in healthy people; any detectable BCR‑ABL1 indicates the BCR‑ABL fusion. For chronic myeloid leukemia monitoring, results use the International Scale (IS): major molecular response (MMR) is ≤0.1% IS; deeper responses include MR4 (≤0.01% IS) and MR4.5 (≤0.0032% IS). Labs may report “undetectable” when below assay sensitivity.

CML is usually a chronic, highly treatable leukemia with tyrosine kinase inhibitors (TKIs) producing long-term, deep molecular remissions and near-normal life expectancy for many patients. A minority who sustain a deep molecular response may stop therapy and remain in treatment‑free remission, often considered a functional cure. Allogeneic stem‑cell transplant can be curative but is reserved for select, high‑risk or resistant cases.

The cost of a BCR‑ABL test varies by country, method and setting. In India private labs typically charge about ₹1,500–₹6,000 for PCR testing. In the US out‑of‑pocket costs commonly range from roughly $100–$500 (higher at some centers). In the UK testing is usually provided free via the NHS for eligible patients. Insurance or public coverage often reduces patient cost.