title: A new phenotype of mitochondrial disease characterized by familial late-onset predominant axial myopathy and encephalopathy.
abstract: Axial myopathy is a rare neuromuscular disease that is characterized by paraspinal muscle atrophy and abnormal posture, most notably camptocormia (also known as bent spine). The genetic cause of familial axial myopathy is unknown. Described here are the clinical features and cause of late-onset predominant axial myopathy and encephalopathy. A 73-year-old woman presented with a 10-year history of severe paraspinal muscle atrophy and cerebellar ataxia. Her 84-year-old sister also developed late-onset paraspinal muscle atrophy and generalized seizures with encephalopathy. Computed tomography showed severe atrophy and fatty degeneration of their paraspinal muscles. Their mother and maternal aunt also developed bent spines. The existence of many ragged-red fibers and cytochrome c oxidase-negative fibers in the biceps brachii muscle of the proband indicated a mitochondrial abnormality. No significant abnormalities were observed in the respiratory chain enzyme activities; however, the activities of complexes I and IV were relatively low compared with the activities of other complexes. Sequence analysis of the mitochondrial DNA from the muscle revealed a novel heteroplasmic mutation (m.602C>T) in the mitochondrial tRNA(Phe) gene. This familial case of late-onset predominant axial myopathy and encephalopathy may represent a new clinical phenotype of a mitochondrial disease.
authors.affiliation: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima City, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sakiyama
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Itsuro
authors.initials: I
authors.lastname: Higuchi
authors.forename: Yukie
authors.initials: Y
authors.lastname: Inamori
authors.forename: Yoko
authors.initials: Y
authors.lastname: Sangatsuda
authors.forename: Kumiko
authors.initials: K
authors.lastname: Michizono
authors.forename: Osamu
authors.initials: O
authors.lastname: Watanabe
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hatakeyama
authors.forename: Yu-ichi
authors.initials: Y
authors.lastname: Goto
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Arimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takashima
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D006801:Humans; D028361:Mitochondrial Diseases / Q000150:complications / Q000235:genetics / Q000473:pathology*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology* / Q000648:ultrastructure; D009468:Neuromuscular Diseases / Q000150:complications / Q000235:genetics / Q000473:pathology*; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV