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**Overview**: FISH inv16 CBFB Panel**Introduction**: The FISH inv16 CBFB Panel is a diagnostic tool designed to detect inv(16) in leukemia using whole blood or bone marrow samples. In India, inv(16)(p13q22) or t(16;16) occurs in ~5-8 percent of acute myeloid leukemia (AML), particularly M4Eo subtype, associated with favorable prognosis and high cure rates with standard chemotherapy. High morbidity from under-testing in rural/low-SES AML patients, limited FISH labs, delayed risk-adapted therapy leading to overtreatment or relapse. Per cytogenetics practices aligned with ICMR and Indian Society of Hematology guidelines, the test employs FISH for CBFB rearrangement over 1-2 days with high sensitivity/specificity, valuable for rapid diagnosis and favorable-risk classification in AML. This diagnostic falls under genetic cancer screening and targets AML patients (especially with eosinophilia or M4/M5 morphology), addressing accurate detection to guide consolidation chemotherapy and avoid unnecessary transplant. With elevated morbidity due to under-testing, the test supports public health efforts by enabling precise molecular subtyping and improving survival. Its blood/bone marrow-based approach ensures reliable inversion detection.**Other Names**: FISH inv16 Pnl.**FDA Status**: FDA approved, CLIA certified for cytogenetics/oncology, compliant with 2025 standards.**Historical Milestone**: inv(16) FISH favorable marker; in India, used in AML protocols.**Purpose**: The test detects 2 parameters including inv(16) CBFB to guide leukemia genetic assessment, identify favorable-risk feature, inform therapy.**Test Parameters**: 1. inv(16) CBFB, 2. Chromosomal Rearrangement.**Pretest Condition**: No fasting required; patients should have confirmed AML.**Specimen**: 3 mL whole blood or bone marrow in 1 EDTA tube, transported within specified times to maintain sample viability.**Sample Stability at Room Temperature**: 48 hours with proper handling to preserve cell viability, ensuring reliable test performance.**Sample Stability at Refrigeration**: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.**Sample Stability at Frozen**: Not applicable (fresh sample preferred for FISH).**Medical History**: Patients should provide details on AML subtype, eosinophilia, prior therapy.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of undetected favorable abnormality including overtreatment, benefits of detection, and minimal discomfort from blood/bone marrow draw.**Procedural Considerations**: The test involves sample processing using FISH by trained personnel to ensure sterile technique, avoid contamination, and interpret results within 1-2 days using provided probes/controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.**Factors Affecting Result Accuracy**: Delays beyond stability periods, improper storage conditions, or low blast count can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Positive inv(16) indicates favorable AML prognosis, necessitating specialist input. Negative may require follow-up.**Specialist Consultation**: Hematologists/oncologists should be consulted for management.**Additional Supporting Tests**: Karyotype, NGS for confirmation.**Test Limitations**: Detects inversion only; comprehensive approach required.**References**: Indian Journal of Hematology 2024, AML Studies India 2023. |
