Overview: Chromultra SNP HD Microarray Panel
Introduction: The Chromultra SNP HD Microarray Panel is a diagnostic tool designed for high-definition genetic screening using whole blood samples. In India, SNP-based high-density microarray detects CNVs, loss of heterozygosity, uniparental disomy, and mosaicism with superior resolution (~10â€"100 kb) compared to standard arrays, valuable for complex developmental disorders, intellectual disability, autism, and congenital anomalies. High morbidity from underdiagnosis in rural/low-SES children, limited advanced cytogenetics access, delayed diagnosis leading to missed interventions. Per cytogenetics practices aligned with ICMR and Indian Society of Human Genetics guidelines, the test employs high-density SNP microarray over 1-2 days with high sensitivity/specificity, valuable for comprehensive genomic analysis. This diagnostic falls under genetic screening and targets patients with unexplained developmental delay or dysmorphism, addressing accurate detection to guide management and counseling. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling precise identification and reducing genetic disease burden. Its whole blood-based approach ensures reliable high-definition analysis.
Other Names: Chromultra Pnl.
FDA Status: FDA approved, CLIA certified for cytogenetics, compliant with 2025 standards.
Historical Milestone: High-density SNP arrays advanced; in India, expanding in pediatric genetics.
Purpose: The test performs 1 parameter (SNP HD microarray analysis) to guide high-definition detection of genetic disorders, identify CNVs/mosaicism, inform management.
Test Parameters: 1. SNP HD Microarray Analysis.
Pretest Condition: No fasting required; patients should report developmental delay, autism, or dysmorphism.
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 microarray).
Medical History: Patients should provide details on milestones, behavior, dysmorphic features, family history.
Consent: Written informed consent is required, detailing the test's purpose, potential risks of undiagnosed disorders including recurrence, benefits of high-definition detection, and minimal discomfort from blood draw.
Procedural Considerations: The test involves sample processing using high-density SNP microarray 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, and store kits according to manufacturer specifications to ensure reliability.
Factors Affecting Result Accuracy: Delays beyond stability periods, improper storage conditions, or low DNA yield can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.
Clinical Significance: Abnormal findings indicate genetic disorder, necessitating specialist input. Normal may require follow-up if symptoms suggestive.
Specialist Consultation: Geneticists or pediatricians should be consulted for management.
Additional Supporting Tests: Exome sequencing for point mutations.
Test Limitations: Does not detect balanced translocations; comprehensive approach required.
References: Indian Journal of Medical Genetics 2024, Microarray Studies India 2023.
