[Friedrich's ataxia: clinical difficulties and genetic possibilities]

Atypical Friedreich's ataxia was diagnosed by DNA-analysis in 4 patients, 2 men aged 70 and 67 and 2 women aged 32 and 37, who had features that included an onset of ataxia after the age of 25, retained tendon reflexes or hyperreflexia, absence of Babinski's sign, and/or a slowly progressive course. Friedreich's ataxia is the most frequent autosomal recessive cerebellar ataxia. Classical characteristics of the disease are a progressive cerebellar ataxia with an onset before the age of 25, loss of lower extremity tendon reflexes, and bilateral Babinski's sign. However, DNA-diagnostic testing based upon the detection of expanded GAA-repeats in the X25-gene, has shown that the clinical spectrum is broader than was previously assumed.