title: POLG1-related and other "mitochondrial Parkinsonisms": an overview.
abstract: Mitochondrial dysfunction has been implicated in the pathogenesis of sporadic, idiopathic Parkinson disease. In some cases, mitochondrial DNA primary genetic abnormalities, or more commonly, secondary rearrangements due to polymerase gamma (POLG1) gene mutation, can directly cause parkinsonism. The case of a Parkinson disease patient with some signs or symptoms suggestive of mitochondrial disease (i.e., ptosis, myopathy, neuropathy) is a relatively common event in the neurological practice. Mitochondrial parkinsonisms do not have distinctive features allowing an immediate diagnosis, and a negative family history does not rule out a possible diagnosis of mitochondrial disorder. In this article, we do not revise the mitochondrial hypothesis of sporadic, idiopathic Parkinson disease, extensively discussed elsewhere, but we review POLG1-related parkinsonism and other well-defined forms of "mitochondrial parkinsonisms", with mtDNA mutations or rearrangements. Lastly, we try to introduce a possible diagnostic approach for patients with parkinsonism and suspected mitochondrial disorder.
authors.affiliation: Department of Neuroscience, Neurological Clinic, University of Pisa, Via Roma 67, 56126 Pisa, Italy. d.orsucci@sssup.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Orsucci
authors.forename: Elena
authors.initials: E
authors.lastname: Caldarazzo Ienco
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Mancuso
authors.forename: Gabriele
authors.initials: G
authors.lastname: Siciliano
mesh_terms: D000074002:DNA Polymerase gamma; D004272:DNA, Mitochondrial / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D003937:Diagnosis, Differential; D020022:Genetic Predisposition to Disease; D006801:Humans; D028361:Mitochondrial Diseases / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D009713:Nucleotidyltransferases / Q000235:genetics; D020734:Parkinsonian Disorders / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*
chemical_list: D004272:DNA, Mitochondrial; D009713:Nucleotidyltransferases; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; C413027:POLG protein, human