Friedreich ataxia (FRDA) is the most common hereditary ataxia disorder, with an estimated prevalence of 1 in 50,000. An autosomal recessive neurodegenerative disorder with a typical age of onset around 5-15 years, FRDA is characterized by progressive gait and limb ataxia, dysarthria, lower-limb areflexia, Babinski sign, loss of position and vibration senses. Cardiomyopathy and diabetes mellitus may also be observed.
Approximately 96% of individuals with FRDA have an abnormally expanded GAA repeat in intron 1 of FXN gene on both alleles (homozygous GAA repeat expansion). The remaining individuals with FRDA are compound heterozygotes for an abnormally expanded GAA repeat in the disease-causing range on one allele and another intragenic pathogenic variant on the other allele. Standard alleles in the FXN gene contain 5 to 60 repeats, while disease-causing alleles can range from 66 to approximately 1300 repeats.
1. Complete & print the test requisition.
- All sections are complete
- You have the correct test code
- Your patient has signed an informed consent
2. Collect patient samples.
Obtain a sample for testing from the patient and confirm that the sample is correctly labeled with the patient’s name and date of birth.
Note: if you do not have a PerkinElmer Genomics kit available in your office, please email or call us at 1-866-354-2910.
3. Send a patient sample.
Ship your test kit back using the pre-paid shipping label. Remember to include:
✔ Completed informed consent
✔ Test requisition form
✔ Any applicable medical records or clinical notes