In spinocerebellar ataxia type 2 (SCA-2), a difference of three CAG repeats distinguishes normal alleles (14 to 31 repeats) from pathogenic alleles (34 to 57 repeats). All sequenced pathogenic alleles have a pure CAG repeat structure, whereas interrupted repeats have been seen exclusively in normal alleles. The authors present two patients with sporadic SCA with an interrupted 34-CAG repeat allele, (CAG)24(CAA)(CAG)9, who showed a phenotype compatible with SCA-2. The interrupted allele coding for a 34 pure polyglutamine tract may cause the SCA phenotype.
|Original language||English (US)|
|Number of pages||3|
|State||Published - Jan 25 2000|
- Interrupted repeats
ASJC Scopus subject areas
- Clinical Neurology