OMIM_backup@xiajingbo:126450-1-DRD2 JSONTXT

This variant, formerly titled MYOCLONUS-DYSTONIA SYNDROME, has been reclassified based on the findings of Klein et al. (2002). In a family of Welsh-Scottish-German origin in which 8 members had alcohol-responsive myoclonus-dystonia (see 159900), Klein et al. (1999) identified a heterozygous G-to-A transition at the first base of codon 154 of the DRD2 gene, resulting in a val154-to-ile (V154I) substitution. By in vitro functional expression assay, Klein et al. (2000)found that the V154I-mutant protein was similar to wildtype and did not show impaired activity. In the same family, Klein et al. (2002)identified a 5-bp deletion in the SGCE gene (604149.0005) in all 8 affected members. The mutation resulted in a frameshift and premature stop. There were 2 unaffected carriers of both mutations. The contribution of each mutation to the clinical phenotype could not be determined, but the phenotype most likely resulted from the SGCE mutation, as Klein et al. (2000) showed that the V154I DRD2 mutant protein was similar to wildtype and did not show impaired activity in in vitro studies.