title: [A case of complex I deficiency with episodic respiratory distress].
abstract: A 7-year-old girl with normal psychomotor development during infancy began to have easy fatigability about 3 years of age. At the age of 5 years, she developed respiratory distress and became unconscious when the serum lactate and pyruvate levels were markedly elevated and a blood gas analysis showed respiratory and metabolic acidosis. Thereafter, she had similar episodic respiratory problems with lactic acidosis. Her muscle biopsy showed a myopathic pattern and numerous ragged-red fibers in an approximately half of muscle fibers. Lipid droplets were slightly to moderately increased in amount mostly in the ragged-red fibers. A biochemical analysis on the isolated mitochondria from the biopsied sample showed markedly decreased NADH cytochrome c reductase activity with no specific but rather uniformly decreased subunits of complex I by the immunoblotting method. She was diagnosed as having the myopathic form of complex I deficiency because she and her relatives with similar muscle symptoms had no central nervous system symptoms such as progressive mental deterioration, convulsions and stroke-like episodes. Diagnosis of complex I deficiency was further confirmed by an oxograph study; the oxygen consumption was not detectable when malate and pyruvate were added as the substrates in the isolated mitochondria. Although stroke-like episodes and convulsions are commonly seen in complex I deficiency, episodic respiratory distress as seen in the present patient has not been described in the literature.
authors.affiliation: Department of Pediatrics, Nagaoka Red Cross Hospital.
authors.forename: J
authors.initials: J
authors.lastname: Tohyama
authors.forename: K
authors.initials: K
authors.lastname: Torigoe
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: R
authors.initials: R
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Suda
authors.forename: M
authors.initials: M
authors.lastname: Tojo
authors.forename: I
authors.initials: I
authors.lastname: Nonaka
authors.forename: Y
authors.initials: Y
authors.lastname: Koga
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Ozawa
mesh_terms: D002648:Child; D004579:Electron Transport; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008931:Mitochondria, Muscle / Q000378:metabolism; D009132:Muscles / Q000473:pathology; D016660:NAD(P)H Dehydrogenase (Quinone); D010101:Oxygen Consumption; D011808:Quinone Reductases / Q000172:deficiency*; D012131:Respiratory Insufficiency / Q000209:etiology* / Q000473:pathology
chemical_list: D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases