title: Novel MTCYB mutation in a young patient with recurrent stroke-like episodes and status epilepticus.
abstract: The acronym "MELAS" (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) denotes patients with histological, biochemical and/or molecular evidence of mitochondrial disease who experience stroke-like episodes. Here we report on a girl with repeated stroke-like episodes and status epilepticus, who was diagnosed with MELAS due to a novel mitochondrial cytochrome b gene (MTCYB) mutation (m.15092G>A, which predicts p.G116S). Western blotting and in silico analyses suggested that this mutation could affect the stability of complex III. Cytochrome b is the only mtDNA-encoded subunit of respiratory chain complex III. Mutations in MTCYB have been associated with isolated mitochondrial myopathy and exercise intolerance, and rarely with multisystem and/or central nervous system involvement. If the m.3243A>G and other common MELAS mutations are absent in several tissues, MTCYB should be sequenced from muscle in patients with stroke-like episodes, especially if muscle histology does not support a mitochondrial myopathy and lactic acidosis is absent.
authors.affiliation: Department of Experimental and Clinical Medicine, Neurological Clinic, University of Pisa, Via Roma 67, Pisa, Italy.
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Mancuso
authors.forename: Claudia
authors.initials: C
authors.lastname: Nesti
authors.forename: Elena Caldarazzo
authors.initials: EC
authors.lastname: Ienco
authors.forename: Daniele
authors.initials: D
authors.lastname: Orsucci
authors.forename: Chiara
authors.initials: C
authors.lastname: Pizzanelli
authors.forename: Alberto
authors.initials: A
authors.lastname: Chiti
authors.forename: Filippo S
authors.initials: FS
authors.lastname: Giorgi
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Meschini
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
authors.forename: Filippo Maria
authors.initials: FM
authors.lastname: Santorelli
authors.forename: Annalisa
authors.initials: A
authors.lastname: Logerfo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Romano
authors.forename: Gabriele
authors.initials: G
authors.lastname: Siciliano
authors.forename: Ubaldo
authors.initials: U
authors.lastname: Bonuccelli
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D001921:Brain / Q000473:pathology; D045303:Cytochromes b / Q000737:chemistry / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D011110:Polymorphism, Genetic; D016415:Sequence Alignment; D013226:Status Epilepticus / Q000175:diagnosis* / Q000235:genetics*; D055815:Young Adult
chemical_list: D045303:Cytochromes b
keywords: cytochrome b; genetics MELAS; mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes; mtDNA; stroke