What is BCR-ABL1 Transcript Screening?

BCR-ABL1 transcript screening refers to the detection and identification of specific fusion transcripts formed by the Philadelphia chromosome (Ph)—a translocation between chromosomes 9 and 22 that results in the BCR-ABL1 fusion gene. This gene encodes an abnormal tyrosine kinase that drives leukemogenesis in various forms of leukemia, particularly chronic myeloid leukemia (CML).

Screening for BCR-ABL1 transcripts is critical for diagnosis, disease classification, prognosis, and guiding therapy decisions, especially regarding tyrosine kinase inhibitors (TKIs). Detection of both common and rare variants can be essential in cases of treatment resistance or atypical clinical presentations.

Role of BCR-ABL1 in Leukemia

BCR-ABL1 was the first chromosomal abnormality identified as causally linked to human cancer. In over 95% of CML cases, breakpoints occur in the major breakpoint cluster region (M-bcr), leading to e13a2 (b2a2) and e14a2 (b3a2) transcripts, both producing the p210 fusion protein.

Less common breakpoints in the minor (m-bcr) and micro (μ-bcr) regions generate e1a2 (p190) and e19a2 (p230), respectively. Rare and atypical fusion transcripts—including e13a3, e14a3, e1a3, e6a2, e6a3, e8a2, e8a3, and e19a3—have also been reported. These may be associated with unusual disease progression or resistance to standard treatments, making comprehensive screening critical.

About the TRUPCR® BCR-ABL1 Transcript Screening Kit

The TRUPCR® BCR-ABL1 Transcript Screening Kit is a real-time PCR (RT-qPCR) assay for the qualitative detection and differentiation of 12 BCR-ABL1 fusion gene transcripts in bone marrow and peripheral blood samples.

Unlike standard assays, this kit offers precise detection of both common (e13a2, e14a2, e1a2, e19a2) and rare (e13a3, e14a3, e1a3, e6a2, e6a3, e8a2, e8a3, e19a3) fusion variants. Each reaction tube is transcript-specific, allowing accurate differentiation. The kit includes an internal control (ABL1) to monitor RNA quality, along with positive controls for all targets, ensuring reliable result interpretation.

Designed for clinical chemistry, hematology, and molecular diagnostics laboratories, this kit provides a streamlined, reliable solution for BCR-ABL1 transcript profiling.

Principle and Workflow

The assay follows a one-step RT-qPCR protocol. Total RNA is reverse-transcribed into cDNA, which is then amplified using fusion-specific primers and probes. The endogenous ABL1 gene serves as a control for RNA integrity and amplification efficiency.

Each fusion transcript is amplified in a dedicated reaction tube. All necessary reagents—including PCR master mix, reverse transcription components, and positive controls—are supplied with the kit, minimizing hands-on time and ensuring reproducibility.

Clinical Application

The TRUPCR® BCR-ABL1 Transcript Screening Kit supports:

• Accurate diagnosis of CML, ALL, and AML with BCR-ABL1 involvement

• Differentiation between typical and atypical transcript variants

• Stratification of patients for tyrosine kinase inhibitor (TKI) therapy

• Detection of rare fusion transcripts in treatment-resistant or unusual cases

By enabling comprehensive transcript screening in a single assay, this kit supports precision medicine in hematological oncology and facilitates timely, evidence-based clinical decision-making.