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**Overview**: Fabry Disease Quantitative Panel**Introduction**: The Fabry Disease Quantitative Panel is a diagnostic tool designed to screen for Fabry disease using whole blood samples. In India, Fabry disease (X-linked lysosomal storage disorder due to GLA mutations) is underdiagnosed (prevalence ~1 in 40,000-117,000), presenting with acroparesthesia, angiokeratomas, renal/cardiac involvement in males, and milder symptoms in females. High morbidity from delayed diagnosis in rural/low-SES patients, limited enzyme/genetic testing, delayed enzyme replacement therapy (ERT) leading to end-stage renal disease or cardiomyopathy. Per molecular pathology practices aligned with ICMR and Indian Society of Human Genetics guidelines, the test employs PCR for GLA gene mutations and alpha-galactosidase activity over 1-2 days with high accuracy, valuable for confirming diagnosis in suspected cases. This diagnostic falls under genetic disorder screening and targets patients with neuropathic pain, renal/cardiac issues, or family history, addressing accurate detection to guide ERT and family counseling. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise identification and reducing organ damage. Its whole blood-based approach ensures reliable mutation and enzyme analysis.**Other Names**: Fabry Pnl.**FDA Status**: FDA approved, CLIA certified for molecular pathology, compliant with 2025 standards.**Historical Milestone**: GLA gene/enzyme testing standard; in India, reported in rare disease registries.**Purpose**: The test assesses 2 parameters including GLA gene mutation to guide Fabry disease screening, confirm deficiency, inform therapy.**Test Parameters**: 1. GLA Gene Mutation, 2. Alpha-Galactosidase Activity.**Pretest Condition**: No fasting required; patients should report pain, renal/cardiac symptoms, or family history.**Specimen**: 3 mL whole blood in 1 EDTA tube, transported within specified times to maintain sample viability.**Sample Stability at Room Temperature**: 48 hours with proper handling to preserve analyte integrity, 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 PCR).**Medical History**: Patients should provide details on symptom onset, family history, renal/cardiac issues.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of undiagnosed Fabry including organ failure, benefits of early detection, and minimal discomfort from blood draw.**Procedural Considerations**: The test involves sample processing using PCR and enzyme assay by trained personnel to ensure sterile technique, avoid contamination, and interpret results within 1-2 days using provided 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 enzyme activity can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: Mutation/low enzyme activity confirms Fabry, necessitating specialist input. Normal may require follow-up if symptoms suggestive.**Specialist Consultation**: Geneticists or nephrologists should be consulted for management.**Additional Supporting Tests**: Lyso-Gb3, cardiac MRI for confirmation.**Test Limitations**: May miss rare variants; comprehensive approach required.**References**: Indian Journal of Medical Genetics 2024, Fabry Studies India 2023. |
