title: A new mitochondria-related disease showing myopathy with episodic hyper-creatine kinase-emia.
abstract: OBJECTIVE
  To elucidate the relationship between mitochondrial DNA (mtDNA) alterations and a mitochondrial disease with a distinct combination of characteristic symptoms, namely episodic hyper-creatine kinase (CK)-emia and mild myopathy.
  
  
  METHODS
  We selected 9 patients with mtDNA np8291 alteration from 586 patients suspected to have a mitochondrial disease, and assessed them clinically, pathologically, and genetically. These 9 patients had undiagnosed mitochondrial myopathy with episodic hyper-CK-emia, all showing similar symptoms and progression.
  
  
  RESULTS
  Patients had mild muscle weakness and episodic hyper-CK-emia triggered by infections or drugs. Five of 9 patients were initially diagnosed with other conditions, such as myasthenia gravis, polymyositis, viral myositis, and drug-induced myopathy, because these conditions were acute or subacute, and 9 patients showed the same 16 mtDNA alterations, which have been reported to be nonpathological polymorphisms. Muscle biopsy revealed ragged-red fibers, highly expressed succinate dehydrogenase staining fibers, and cytochrome c oxidase-deficient fibers. Because their mitochondrial sequence data was almost the same, and 9 patients live in widely separated cities in Japan, the alterations may have arisen from a single source.
  
  
  CONCLUSIONS
  These findings suggest that mild myopathy with episodic hyper-CK-emia associated with some of the 16 mtDNA alterations or at least with their mitochondria, could be a novel mitochondrial disease. Therefore, we propose that this disease be named as "mitochondrial myopathy with episodic hyper-CK-emia (MIMECK)." These alterations could work concomitantly and probably modify the impact of medications or other environmental factors. We believe these findings provide an insight into a novel aspect of mitochondrial disease pathogenesis.
authors: Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
authors: Yuji
authors: Y
authors: Okamoto
authors: Itsuro
authors: I
authors: Higuchi
authors: Yusuke
authors: Y
authors: Sakiyama
authors: Shoko
authors: S
authors: Tokunaga
authors: Osamu
authors: O
authors: Watanabe
authors: Kimiyoshi
authors: K
authors: Arimura
authors: Masanori
authors: M
authors: Nakagawa
authors: Hiroshi
authors: H
authors: Takashima
mesh_terms: D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood*; D004272:DNA, Mitochondrial / Q000378:metabolism; D030541:Databases, Genetic; D018450:Disease Progression; D005260:Female; D019694:Hepatitis B, Chronic / Q000150:complications; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D008297:Male; D008875:Middle Aged; D028361:Mitochondrial Diseases / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D018908:Muscle Weakness / Q000209:etiology; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology; D009135:Muscular Diseases / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D010146:Pain / Q000209:etiology; D011110:Polymorphism, Genetic
chemical_list: D004272:DNA, Mitochondrial; D003402:Creatine Kinase