BCR-ABL in Dehradun

What is a BCR-ABL?

BCR-ABL is an abnormal fusion gene created when parts of chromosomes 9 and 22 swap places, producing the shortened chromosome 22 known as the Philadelphia chromosome. The resulting protein is a permanently switched-on enzyme that drives uncontrolled white cell production, and it is the defining abnormality of chronic myeloid leukaemia. Detecting it establishes the diagnosis. Quantifying it does something arguably more remarkable: because the abnormality is specific to the leukaemic cells, measuring how much BCR-ABL transcript remains gives a direct measure of how much disease is left, down to very low levels. This is the basis of one of the great successes of modern medicine. Targeted drugs known as tyrosine kinase inhibitors block the abnormal protein specifically, and CML has been transformed from a fatal illness into a condition most patients live with normally. Treatment response is defined by BCR-ABL levels on an international scale, with defined milestones at three, six and twelve months, and failure to reach them prompts a change of drug or testing for resistance mutations.

Why take this test?

BCR-ABL testing is indicated where chronic myeloid leukaemia is suspected, typically after a blood count shows a markedly raised white cell count with immature forms, often found incidentally or alongside fatigue, weight loss, night sweats, abdominal fullness from an enlarged spleen, or easy bruising. Once the diagnosis is made, the quantitative test becomes the central monitoring tool, repeated at defined intervals to confirm the treatment is achieving its milestones and later to watch for relapse. It is also used to assess eligibility for stopping treatment in patients with a sustained deep response, which is now possible for a proportion of patients under specialist supervision. This is a haematologist-directed test throughout. Use the same laboratory for serial monitoring wherever possible, since results are reported on an international scale but small methodological differences matter when tracking a falling curve over years.

• A markedly raised white cell count with immature forms
• Fatigue, weight loss, night sweats or abdominal fullness
• An enlarged spleen found on examination
• Confirming a diagnosis of chronic myeloid leukaemia
• Monitoring response against defined treatment milestones
• Assessing eligibility for treatment discontinuation under specialist care

FAQs: BCR-ABL in Dehradun