Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant spinocerebellar ataxia caused by CAG triplet expansion in atrophin 1 and is frequently associated with cerebral white matter lesions.
To find other factors involved in this variability, we performed a regression analysis in 1255 affected individuals with identified expansions (spinocerebellar ataxia types 1, 2, 3, 6 and 7), recruited through the European Consortium on Spinocerebellar Ataxias, to determine whether age at onset is influenced by the size of the normal allele in eight causal (CAG)n-containing genes (ATXN1-3, 6-7, 17, ATN1 and HTT).
Sixteen independent patients with involuntary movements, psychiatric disturbances and ataxia not having a HTT mutation were searched for loci PRNP (prion protein, HDL1), JPH3 (HDL2), ATN1 (dentatorubral-pallidoluysian atrophy), ATX2 (spinocerebellar ataxia 2) ATXN3 (spinocerebellar ataxia 3), and TBP (spinocerebellar ataxia 17=HDL4).
Genetic analysis excluded the presence of pathological repeat expansions in spinocerebellar ataxia (SCA) types 1-3, 6-8, 10, 12 and 17, and DRPLA genes.
The autosomal dominant spinocerebellar ataxias (SCAs) are a clinical and genetically heterogeneous group of debilitating, neurodegenerative diseases, related to fourteen different loci - SCAs 1, 2, 4, 5, 6, 7, 8, 10, 11,12,13 and 14, Machado-Joseph disease (MJD/SCA 3), and DRPLA.
To identify various subtypes of spinocerebellar ataxias (SCAs) among 57 unrelated individuals clinically diagnosed as ataxia patients we analysed the SCA1, SCA2, SCA3, SCA6, SCA7 and DRPLA loci for expansion of CAG repeats.
The autosomal dominant spinocerebellar ataxias (SCAs) are a group of late-onset, neurodegenerative disorders for which 10 loci have been mapped (SCA1, SCA2, SCA4-SCA8, SCA10, MJD, and DRPLA).