TY - JOUR 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 SP - 661 LP - 664 DO - 10.1136/jnnp.68.5.661 VL - 68 IS - 5 AU - Melissa L McCormack AU - Rodney P Guttmann AU - Matthew Schumann AU - Jennifer M Farmer AU - Catherine A Stolle AU - Victoria Campuzano AU - Michel Koenig AU - David R Lynch Y1 - 2000/05/01 UR - http://jnnp.bmj.com/content/68/5/661.abstract N2 - 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. ER -