[Genetic tests: how far should we go? A case of late-onset Friedreich's disease]

Two sisters developed isolated cerebellar ataxia with pyramidal signs and preservation of reflexes at 49 and 63 years of age. Presence of two abnormal expansions GAA on both allels of the frataxine gene led to the diagnosis of Friedreich ataxia. These cases demonstrate the place of genetic tests in the diagnosis of late onset autosomal recessive ataxia.