Friedreich Ataxia Repeat Analysis (FXN repeat)
Use
Repeat expansion analysis of the FXN gene to assess GAA trinucleotide repeat expansions for diagnosis of Friedreich ataxia, which is characterized by progressive gait and limb ataxia, dysarthria, sensory loss, cardiomyopathy, and diabetes. Severity and age of onset correlate with length of GAA repeat expansion. This assay addresses the diagnostic need for identifying GAA repeat expansions that are the disease mechanism in most affected individuals.
Special Instructions
Orderable through Neuro‐TRF menu; GeneDx CLIA‑certified, CAP‑accredited, holds NY state license. Samples begin processing after billing and clinical review. See GeneDx DNA requirements for extracted DNA submissions testing.
Limitations
This test analyzes only GAA repeat expansions in intron 1 of FXN and does not detect point mutations, deletions, duplications or other variant types. Somatic mosaicism and repeat instability may lead to variability relative to other tissues. Does not detect non‑expansion variants.
Methodology
PCR-based (PCR)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Other
Volume
Not provided
Minimum Volume
Not provided
Other tests from different labs that may be relevant