Early-Onset Friedreich's Ataxia With Oculomotor Apraxia

Amene Saghazadeh, Sina Hafizi, Firouzeh Hosseini, Mahmoud Reza Ashrafi, Nima Rezaei; Acta Medica Iranica 2017. 55(2):128-130.

Here we described two siblings with the concurrence of early onset FRDA and oculomotor apraxia. However, initially, it appeared that AOA1 was more probable than FRDA, as AOA1 is typically diagnosed in young children (mean age at onset=6.8±4.8), while the mean age of onset for FRDA patients is around 10.52 years. Overlapping clinical features between AOA1 and FRDA necessitate laboratory tests and genetic studies for GAAtrinucleotide repeat expansion and Aprataxin gene which are mainly considered to be responsible for FRDA and AOA1, respectively. Due to the normal laboratory test results and given that AOA1 is associated with hypercholesterolemia; the diagnosis was more likely to be FRDA rather than AOA1.
First, those neurologists should bear in mind that clinical presentations of FRDA may vary widely from the classical phenotype of gait and limb ataxia to atypical manifestations such as oculomotor apraxia. Second, that laboratory test results might provide us with valuable information for differential diagnosis between FRDA and AOA, particularly when genetic analysis cannot be performed. Third, that genetic analysis is presently acknowledged as the most powerful tool for differential diagnosis between inherited ataxias.