DYT1 mutations amongst adult primary dystonia patients in Singapore with review of literature comparing East and West

Abstract

Background: Dystonia is a heterogenous group of movement disorders whose clinical spectrum is very wide. At least 13 different genes and gene loci have been reported. While a 3-bp deletion in the DYT1 gene is the most frequent cause of early limb-onset, generalized dystonia, it has also been found in non-generalized forms of sporadic dystonia. An 18-bp deletion in the DYT1 gene has also been reported. Objectives: We screened for the 3-bp and 18-bp deletions in the DYT1 gene among our sporadic, adult-onset primary dystonia patients in Singapore. We reviewed the literature to compare the frequency of DYT1 mutation between the East and the West. Methods: We screened 54 patients with primary dystonia (focal: n = 41; segmental: n = 11; multifocal: n = 1; generalized: n = 1) for the deletions in the DYT1 gene. A careful review of all published literature on DYT1 screening among sporadic, non-familial, non-Ashkenazi Jewish patients was done. Results: We did not detect any mutations in the exon 5 of the DYT1 gene in any of our patients. The frequency of DYT1 mutation amongst Asians (1.0%) was comparable to the West (1.56%) (p = NS). Conclusions: DYT1 mutations are uncommon amongst adult primary dystonia patients in Singapore. © 2006 Elsevier B.V. All rights reserved.