title: POLG1 mutations and stroke like episodes: a distinct clinical entity rather than an atypical MELAS syndrome.
abstract: BACKGROUND
  POLG1 mutations have been associated with MELAS-like phenotypes. However given several clinical differences it is unknown whether POLG1 mutations are possible causes of MELAS or give raise to a distinct clinical and genetic entity, named POLG1-associated encephalopathy.
  
  
  METHODS
  We describe a 74 years old man carrying POLG1 mutations presenting with strokes, myopathy and ragged red fibers with some atypical aspects for MELAS such as late onset, lack of cerebral calcification and presence of frontal and occipital MRI lesions better consistent with the POLG associated-encephalopathy spectrum.
  
  
  CONCLUSIONS
  The lack of available data hampers a definite diagnosis in our patient as well as makes it difficult to compare MELAS, which is a clearly defined clinical syndrome, with POLG1-associated encephalopathy, which is so far a purely molecularly defined syndrome with a quite heterogeneous clinical picture. However, the present report contributes to expand the phenotypic spectrum of POLG1 mutations underlining the importance of searching POLG1 mutations in patients with mitochondrial signs and MELAS like phenotypes but negative for common mtDNA mutations.
authors: Neurological Unit, Ospedale di Desio, Azienda Ospedaliera di Desio Vimercate, Monza, Italy.
authors: Antonella
authors: A
authors: Cheldi
authors: Dario
authors: D
authors: Ronchi
authors: Andreina
authors: A
authors: Bordoni
authors: Bianca
authors: B
authors: Bordo
authors: Silvia
authors: S
authors: Lanfranconi
authors: Maria Grazia
authors: MG
authors: Bellotti
authors: Stefania
authors: S
authors: Corti
authors: Valeria
authors: V
authors: Lucchini
authors: Monica
authors: M
authors: Sciacco
authors: Maurizio
authors: M
authors: Moggio
authors: Pierluigi
authors: P
authors: Baron
authors: Giacomo Pietro
authors: GP
authors: Comi
authors: Antonio
authors: A
authors: Colombo
authors: Anna
authors: A
authors: Bersano
mesh_terms: D000368:Aged; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005820:Genetic Testing; D006801:Humans; D017241:MELAS Syndrome / Q000150:complications / Q000235:genetics* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D020521:Stroke / Q000150:complications / Q000235:genetics* / Q000473:pathology
chemical_list: D003576:Electron Transport Complex IV; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; C413027:POLG protein, human