Overview: FISH 17p Panel
Introduction: The FISH 17p Panel is a diagnostic tool designed to detect 17p deletion in leukemia using whole blood or bone marrow samples. In India, 17p deletion (TP53 locus) occurs in ~5-10 percent of chronic lymphocytic leukemia (CLL) and ~10 percent of acute myeloid leukemia (AML), associated with poor prognosis, chemoresistance, and short survival. High morbidity from under-testing in rural/low-SES leukemia patients, limited FISH labs, delayed targeted therapy (e.g., venetoclax/ibrutinib in CLL) leading to treatment failure. Per cytogenetics practices aligned with ICMR and Indian Society of Hematology guidelines, the test employs FISH for 17p deletion over 1-2 days with high sensitivity/specificity, valuable for risk stratification in CLL/AML. This diagnostic falls under genetic cancer screening and targets leukemia patients (especially CLL with poor-risk features), addressing accurate detection to guide novel agents or trials. 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 17p Pnl.
FDA Status: FDA approved, CLIA certified for cytogenetics/oncology, compliant with 2025 standards.
Historical Milestone: 17p FISH prognostic; in India, used in CLL protocols.
Purpose: The test detects 2 parameters including 17p deletion to guide leukemia genetic assessment, identify high-risk features, inform therapy.
Test Parameters: 1. 17p Deletion, 2. Chromosomal Rearrangement.
Pretest Condition: No fasting required; patients should have confirmed leukemia.
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 17p deletion including poor 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: Positive 17p deletion indicates high-risk leukemia, necessitating specialist input. Negative may require follow-up.
Specialist Consultation: Hematologists/oncologists should be consulted for management.
Additional Supporting Tests: TP53 sequencing, karyotype for confirmation.
Test Limitations: Detects deletion only; comprehensive approach required.
References: Indian Journal of Hematology 2024, Leukemia Studies India 2023.
