Overview: NGS Familial Hemiplegic Migraine Sequencing TestIntroduction: The NGS Familial Hemiplegic Migraine Sequencing Test sequences genes to diagnose familial hemiplegic migraine, causing severe headaches or paralysis. Aligned with 2023 AAN guidelines, it uses PCR for high specificity, supporting neurological screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in molecular pathology for patients with suspected familial hemiplegic migraine (FHM).
Other Names: FHM Assay, CACNA1A/ATP1A2 Gene Test.
FDA Status: Laboratory-developed test (LDT), meeting molecular pathology standards for diagnostic accuracy.
Historical Milestone: FHM sequencing began in the 1990s with migraine genetic research. NGS methods improved in the 2010s, enhancing diagnostic precision.
Purpose: Sequences genes to diagnose FHM, guides treatment, and evaluates patients with severe headaches or paralysis.
Test Parameters: 1. FHM Genes
Pretest Condition: No fasting required. Collect whole blood, buccal swab, or saliva. Report history of severe headaches, paralysis, or FHM 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 severe headaches, transient paralysis, aura, or family history of FHM. Include current medications, especially migraine prophylactics.
Consent: Written consent required, detailing the tests purpose, FHM implications, and risks of sample collection.
Procedural Considerations: Uses next-generation sequencing to analyze FHM genes (e.g., CACNA1A, ATP1A2). Results are available in 3-5 days, supporting clinical decisions. Performed in laboratories, often for FHM diagnosis.
Factors Affecting Result Accuracy: Low DNA yield or improper sample storage can affect results. Contamination may reduce specificity.
Clinical Significance: Identified mutations confirm FHM, guiding prophylactic therapy or genetic counseling. Negative results may require broader migraine panels.
Specialist Consultation: Consult a neurologist for result interpretation and treatment planning.
Additional Supporting Tests: EEG, brain MRI, or clinical migraine evaluation to confirm FHM diagnosis.
Test Limitations: Not all FHM cases are genetic; clinical correlation is needed. Sample quality affects sensitivity.
References: AAN Migraine Guidelines, 2023; Neurology, Russell MB, 2022.
