A Task Force was created by the International Parkinson and Movement Disorders Society in 2012 with the aim of analyzing apparent problems and providing solutions regarding the current nomenclature of genetic movement disorders. Their suggestions have been published,1. and aim to tackle several drawbacks of the current locus assignment system, such as 1) the inability to distinguish disease-causing mutations from genetic risk factors, 2) inconsistent associations with phenotype, 3) failure to assign a locus symbol in some established movement disorders, 4) more than one symbol being assigned for the same disorder, 5) unconfirmed genotype-phenotype associations, 6) erroneous labels and 7) symbol designation in the absence of known locus or gene. The proposed nomenclature suggests that a disorder should be listed only if the causative gene is already known (i.e. genetic testing is possible), and appropriate prefixes should be assigned according to the core phenotypic feature, followed by the causative gene (e.g. DYT-gene1, PARK-gene2, HSP-gene3). Thus, currently used locus numbers are eliminated from future medical terminology (e.g. DYT1, PARK6,…). Suggested designations derive from primary clinical phenomenology: genetically determined parkinsonism, dystonia, chorea, paroxysmal movement disorders, dominant cerebellar ataxia, and spastic paraplegia. Two groups of genetically determined disorders are prefixed not according to phenotype but typical imaging instead: primary familial brain calcification (PFBC-gene1, PFBC-gene2,…) and neurodegeneration with brain iron accumulation (NBIA-gene1, NBIA-gene2,…). Rules have been defined for disorders featuring mixed core characteristics. Future work will focus on as yet not approached disorders such as myoclonus, as well as x-linked, recessive, and congenital ataxias.
1. Marras C, et al. Nomenclature of genetic movement disorders: Recommendations of the international Parkinson and movement disorder society task force. Movement Disorders 2016;31(4):436-57.
Link to full text (PubMed): www.ncbi.nlm.nih.gov/pubmed/27079681