RT Journal Article SR Electronic T1 Frataxin point mutations in two patients with Friedreich's ataxia and unusual clinical features JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 661 OP 664 DO 10.1136/jnnp.68.5.661 VO 68 IS 5 A1 Melissa L McCormack A1 Rodney P Guttmann A1 Matthew Schumann A1 Jennifer M Farmer A1 Catherine A Stolle A1 Victoria Campuzano A1 Michel Koenig A1 David R Lynch YR 2000 UL http://jnnp.bmj.com/content/68/5/661.abstract AB Two patients with a progressive ataxia are presented with clinical features consistent with classic Friedreich's ataxia (FRDA), but also with features unusual for FRDA. Analysis of DNA showed that each patient is heterozygous for the expanded GAA repeat of FRDA, but carries a base change on his other frataxin allele. For one patient a non-conservative arginine to cysteine amino acid change is predicted at amino acid 165 whereas the other mutation is found at the junction of exon one and intron one. Muscle biopsy showed an absence of frataxin immunoreactivity in the patient harbouring the intronic mutation, confirming the pathological nature of the base change. These mutations extend the range of point mutations seen in FRDA, and agree with recent reports suggesting phenotypic variation in patients with FRDA harbouring point mutations in conjunction with an expanded GAA repeat.