FRDA Flashcards
What is the mode of inheritance for FRDA?
Autosomal Recessive
Name 5 clinical features associated with FRDA
Slurred speech, muscle weakness, lower limbs spasticity, scoliosis, cardiomyopathy (2/3 patients), diabetes (30%), bladder dysfunction.
What is the age of onset for FRDA?
<25, Mean age is between 10-15 years of age.
25% of patients have atypical FRDA, how is atypical FRDA characterised?
Later age of onset, retained tendon reflexes or unusually slow disease progression.
What is the carrier frequency for FRDA?
1:100
Pathogenic variants in which gene causes FRDA?
FXN, which encodes a protein called Frataxin
Little is understood about the function of the Frataxin protein but it’s noted to be important in the _______ function.
Mitochondrial
The expansion of which triplet repeat is associated with FRDA?
GAA
In which intron does the expansion of the GAA triplet repeat cause FRDA?
Intron 1
If a diagnostic patient is shown to have a heterozygous GAA repeat expansion, is any further testing offered
Testing for point mutation in FXN gene
Are homozygous expansion and compound heterozygous patients clinically different?
No
