title: Evaluating clinical mitochondrial respiratory chain enzymes from biopsy specimens presenting skewed probability distribution of activity data.
abstract: Due to the relative rarity of mitochondrial diseases, generating reference ranges is problematic in evaluation of respiratory chain activities particularly in pediatric cases. We determined the sample distribution of respiratory chain enzyme activities in skeletal muscle biopsies collected from pediatric patients suspected of neuromuscular disorders. Activities of NADH-ubiquinone reductase, NADH-cytochrome c reductase, succinate-cytochrome c reductase; ubiquinol-cytochrome c reductase and cytochrome c oxidase activities have log-normal distributions even when confirmed mitochondrial diseases were ruled out. Impact of the log-normal distribution of the respiratory chain enzyme activities on clinical diagnostics is discussed.
authors.affiliation: PEDEGO Research Unit and Medical Research Center Oulu, University of Oulu, Finland; Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Finland. Electronic address: milla-riikka.hautakangas@oulu.fi.
authors.forename: Milla-Riikka
authors.initials: MR
authors.lastname: Hautakangas
authors.affiliation: PEDEGO Research Unit and Medical Research Center Oulu, University of Oulu, Finland; Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Finland. Electronic address: reetta.hinttala@oulu.fi.
authors.forename: Reetta
authors.initials: R
authors.lastname: Hinttala
authors.affiliation: PEDEGO Research Unit and Medical Research Center Oulu, University of Oulu, Finland; Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Finland. Electronic address: heikki.rantala@oulu.fi.
authors.forename: Heikki
authors.initials: H
authors.lastname: Rantala
authors.affiliation: Medical Informatics and Statistics Group, University of Oulu, Finland. Electronic address: pentti.nieminen@oulu.fi.
authors.forename: Pentti
authors.initials: P
authors.lastname: Nieminen
authors.affiliation: PEDEGO Research Unit and Medical Research Center Oulu, University of Oulu, Finland; Department of Children and Adolescents, Division of Pediatric Neurology, Oulu University Hospital, Finland. Electronic address: johanna.uusimaa@oulu.fi.
authors.forename: Johanna
authors.initials: J
authors.lastname: Uusimaa
authors.affiliation: Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland. Electronic address: ilmo.hassinen@oulu.fi.
authors.forename: Ilmo E
authors.initials: IE
authors.lastname: Hassinen
mesh_terms: D000293:Adolescent; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D045222:Electron Transport Chain Complex Proteins / Q000032:analysis*; D005260:Female; D006802:Human Activities; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D028361:Mitochondrial Diseases / Q000175:diagnosis*; D017240:Mitochondrial Myopathies / Q000175:diagnosis*; D018482:Muscle, Skeletal / Q000473:pathology*; D009422:Nervous System Diseases / Q000175:diagnosis*
chemical_list: D045222:Electron Transport Chain Complex Proteins
keywords: Log-normal statistics; Mitochondrial diagnostics; Respiratory chain; Skeletal muscle