Analysis of SCA-2 and SCA-3 repeats in Parkinsonism: evidence of SCA-2 expansion in a family with autosomal dominant Parkinson's disease.

The spinocerebellar ataxias (SCAs) are progressive neurodegenerative disorders linked to more than 20 genetic loci. Most often, these diseases are caused by expansion of triplet repeats encoding polyglutamine (polyQ) tracts. The phenotype is variable and can cause a disease that overlaps clinically with Parkinson's disease (PD).

Analysis of the PINK1 gene in a large cohort of cases with Parkinson disease.

Background: Mutations in the PTEN-induced kinase (PINK1) gene located within the PARK6 locus on chromosome 1p35-p36 have recently been identified in patients with recessive early-onset Parkinson disease.

Objective: To assess the prevalence of PINK1 mutations within a series of early- and late-onset Parkinson disease patients living in North America.

Design: All coding exons of the PINK1 gene were sequenced in a series of 289 Parkinson disease patients and 80 neurologically normal control subjects; the mutation frequencies were evaluated in additional controls (100 white and 50 Filipino subjects).