|
**Overview**: FISH 13q Deletion Panel**Introduction**: The FISH 13q Deletion Panel is a diagnostic tool designed to detect 13q deletion in leukemia using whole blood or bone marrow samples. In India, del(13q) is the most common cytogenetic abnormality in chronic lymphocytic leukemia (CLL) (~50-60 percent of cases) and occurs in some acute leukemias, associated with favorable prognosis in isolated del(13q) CLL but poor when combined with other changes. High morbidity from under-testing in rural/low-SES leukemia patients, limited FISH access, delayed risk-adapted treatment leading to suboptimal outcomes. Per cytogenetics practices aligned with ICMR and Indian Society of Hematology guidelines, the test employs FISH for 13q deletion over 1-2 days with high sensitivity/specificity, valuable for prognostic stratification in CLL and differential diagnosis in other leukemias. This diagnostic falls under genetic cancer screening and targets CLL or leukemia patients, addressing accurate detection to guide watch-and-wait vs. therapy in CLL. With elevated morbidity due to under-testing, the test supports public health efforts by enabling precise molecular prognostication and improving survival. Its blood/bone marrow-based approach ensures reliable deletion detection.**Other Names**: FISH 13q Pnl.**FDA Status**: FDA approved, CLIA certified for cytogenetics/oncology, compliant with 2025 standards.**Historical Milestone**: 13q FISH prognostic; in India, used in CLL protocols.**Purpose**: The test detects 2 parameters including 13q deletion to guide leukemia genetic assessment, identify favorable/high-risk features, inform therapy.**Test Parameters**: 1. 13q Deletion, 2. Chromosomal Rearrangement.**Pretest Condition**: No fasting required; patients should have confirmed leukemia/CLL.**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 leukemia subtype, stage, prior therapy.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of undetected abnormalities including suboptimal prognosis, 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 tumor burden can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Isolated 13q deletion indicates favorable CLL prognosis; combined changes may require specialist input.**Specialist Consultation**: Hematologists/oncologists should be consulted for management.**Additional Supporting Tests**: Full CLL FISH panel, karyotype for confirmation.**Test Limitations**: Detects deletion only; comprehensive approach required.**References**: Indian Journal of Hematology 2024, Leukemia Studies India 2023. |
