¹Department of Medical Genetics, University Medical Center, Stratenum, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands

Correspondence: DS Verbeek, University Medical Center Utrecht Stratenum Universiteitsweg 100 3584 CG Utrecht, The Netherlands. Tel: +31 30 2538939; Fax: +31 30 2538479; E-mail: D.S.Verbeek@med.uu.nl

Received 23 September 2003; Revised 22 December 2003; Accepted 7 January 2004; Published online 17 March 2004.

Abstract

This pilot study was initiated to show the existence of founder effects in the Dutch autosomal dominant cerebellar ataxia (ADCA) population. The ADCAs comprise a clinically heterogeneous group of neurodegenerative disorders and the estimated prevalence in the Netherlands is approximately 3:100 000 individuals. Here, we focused on the SCA3 and SCA6 genes because mutations in these genes occur most frequently in the Netherlands. We were able to determine a common origin of the CAG repeat expansions in the majority of Dutch SCA3 and SCA6 families. Haplotype analysis and linkage disequilibrium studies with polymorphic markers revealed shared haplotypes surrounding the SCA3 and SCA6 genes. These results strongly suggest that ADCA families can be traced back to common ancestors in particular parts of the Netherlands.