Generalized chorea in two patients harboring the Friedreich's ataxia gene trinucleotide repeat expansion.

Recently, a trinucleotide repeat expansion in intron 1 of the frataxin gene on chromosome 9p13 has been identified as the genetic defect in Friedreich's ataxia (FA). We have identified two patients exhibiting generalized chorea in the absence of cerebellar signs who were homozygous for this intron 1 expansion. Chorea as a rare manifestation of FA has previously been controversial. This is the first report of chorea in patients confirmed to have the FA genetic abnormality and broadens further the clinical phenotype associated with the FA genotype.