Genetics of essential tremor.

Essential tremor (ET), the cause of which remains poorly understood, is one of the most common neurological disorders. While environmental agents have been proposed to play a role, genetic factors are believed to contribute to its onset. Thus far, three gene loci (ETM1 on 3q13, ETM2 on 2p24.1 and a locus on 6p23) have been identified in patients and families with the disorder. In addition, a Ser9Gly variant in the dopamine D3 receptor gene on 3q13 has been suggested to be a risk factor. Moreover, genetically deficient animal models express a phenotype that overlaps with some clinical characteristics of the human form of the illness. Further analyses of these genetic abnormalities may lead to the identification of causative mutations and a better understanding of the molecular mechanisms in this common movement disorder.