Case-control study of patients with essential tremor in Latvia

Background: Essential tremor (ET) is the most prevalent inherited movement disorder. ET has been mapped on chromosomes 2 and 3, but causative genes are not known. Methods: We genotyped 16 microsatellite markers in a case-control cohort consisting of 104 patients and 116 controls. Results: No significant difference between allele frequencies was found. The highest difference of frequencies was found in allele 171 of the marker D2S220 (OR 0.13, 95% CI 0.02-1.03, P = 0.05). In addition, we investigated the distribution of suspected disease gene DRD3 Ser9Gly polymorphism in the same patients and controls. Conclusion: There was not a significant difference in genotypic distribution between disease group and control subjects (χ² = 2.8, P = 0.25).