Rare causes of dystonia parkinsonism

The list of genetic causes of syndromes of dystonia parkinsonism grows constantly. As a consequence, the diagnosis becomes more and more challenging for the clinician. Here, we summarize the important causes of dystonia parkinsonism including autosomal-dominant, recessive, and x-linked forms. We cover dopa-responsive dystonia, Wilson's disease, Parkin-, PINK1-, and DJ-1-associated parkinsonism (PARK2, 6, and 7), x-linked dystonia-parkinsonism/Lubag (DYT3), rapid-onset dystonia-parkinsonism (DYT12) and DYT16 dystonia, the syndromes of Neurodegeneration with Brain Iron Accumulation (NBIA) including pantothenate kinase (PANK2)- and PLA2G6 (PARK14)-associated neurodegeneration, neuroferritinopathy, Kufor-Rakeb disease (PARK9) and the recently described SENDA syndrome; FBXO7-associated neurodegeneration (PARK15), autosomal-recessive spastic paraplegia with a thin corpus callosum (SPG11), and dystonia parkinsonism due to mutations in the SLC6A3 gene encoding the dopamine transporter. They have in common that in all these syndromes there may be a combination of dystonic and parkinsonian features, which may be complicated by pyramidal tract involvement. The aim of this review is to familiarize the clinician with the phenotypes of these disorders.