Overview: NGS Whole Exome Sequencing TestIntroduction: The NGS Whole Exome Sequencing Test sequences the entire exome to diagnose complex genetic disorders, causing various symptoms. Following 2023 ACMG guidelines, it uses PCR for high specificity, supporting genetic screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in molecular pathology for patients with suspected complex genetic disorders.
Other Names: Whole Exome NGS Assay, Clinical Exome Test.
FDA Status: Laboratory-developed test (LDT), meeting molecular pathology standards for diagnostic accuracy.
Historical Milestone: Whole exome sequencing began in the 2000s with genomic research. NGS methods improved in the 2010s, enhancing diagnostic precision.
Purpose: Sequences the entire exome to diagnose complex genetic disorders, guides treatment, and evaluates patients with various symptoms.
Test Parameters: 1. Whole Exome Sequence
Pretest Condition: No fasting required. Collect whole blood, buccal swab, or saliva. Report history of developmental delays, congenital anomalies, or genetic symptoms.
Specimen: Whole Blood (EDTA, 2-5 mL), Buccal Swab (sterile swab, 1-2 swabs), Saliva (sterile container, 1-2 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 48 hours
Sample Stability at Frozen: Not frozen
Medical History: Document developmental delays, congenital anomalies, neurological issues, or family history of genetic disorders. Include current medications, especially symptom-specific treatments.
Consent: Written consent required, detailing the tests purpose, genetic disorder implications, and risks of sample collection.
Procedural Considerations: Uses next-generation sequencing to analyze the entire exome. Results are available in 3-5 days, supporting clinical decisions. Performed in laboratories, often for complex genetic disorder diagnosis.
Factors Affecting Result Accuracy: Low DNA yield or improper sample storage can affect results. Contamination may reduce specificity.
Clinical Significance: Identified mutations confirm genetic disorders, guiding targeted therapy or genetic counseling. Negative results may require whole-genome sequencing.
Specialist Consultation: Consult a geneticist for result interpretation and treatment planning.
Additional Supporting Tests: Karyotyping, microarray, or specific gene panels to confirm genetic disorder diagnosis.
Test Limitations: Not all genetic disorders are exome-based; clinical correlation is needed. Sample quality affects sensitivity.
References: ACMG Genetic Testing Guidelines, 2023; American Journal of Human Genetics, Bamshad MJ, 2022.
