Lack of association with TorsinA haplotype in German patients with sporadic dystonia

Abstract

Genetic variability at loci underlying autosomal dominant forms of neurologic diseases may also contribute to the risk of developing sporadic disease. The most common cause of autosomal dominantly inherited, primary generalized dystonia is a deletion of a glutamate codon (GAG) in the TorsinA gene on chromosome 9q34.1 Sporadic (typically focal) dystonia is considerably more common. A strong association of sporadic dystonia with the TorsinA haplotype T2 was recently reported in the Icelandic population.2 The use of population isolates in genetic studies is increasingly popular. However, genetic and environmental homogeneity does not reflect the diversity of humankind as a whole. Furthermore, genetic drift influences the genotypic makeup of population isolates. Thus, findings derived from studies of population isolates need to be replicated in normal, out-bred populations to confirm their relevance outside the population isolate.3 We explored whether sporadic dystonia is also associated with any of the TorsinA haplotypes in a more typical, nonisolated population. We assessed TorsinA haplotypes …