title: Fatal infantile mitochondrial cardiomyopathy and myopathy with heterogeneous tissue expression of combined respiratory chain deficiencies.
abstract: A 5-month-old boy died of progressive heart failure that started at the age of 3 months. Autopsy revealed a mitochondrial cardiomyopathy and a mitochondrial myopathy of the limb muscle and diaphragm. Cytochemically random defects of cytochrome c oxidase were visualized by light and electron microscopy in the diaphragm and especially the heart muscle, the limb muscle showing a diffuse attenuation whereas the liver and kidneys reacted normally. The activities of NADH-dehydrogenase (complex I) and cytochrome c oxidase (complex IV) were severely diminished (20% residual activity of controls) in the skeletal and heart muscle. In the heart, succinate cytochrome c reductase (complex II/III) was additionally decreased to the same degree. Loss of cytochrome c oxidase activity was based on a reduction of both mitochondrial and nuclear derived subunits in the heart and diaphragm as revealed by immunohistochemical analysis, whereas the limb muscle showed a normal immunoreactive protein content. The results illustrate heterogeneous tissue expression of respiratory chain enzyme defects and demonstrate that a cardiomyopathy may be the leading presentation of a mitochondrial disorder in early infancy.
authors.affiliation: Pathologisches Institut, Universität München, Federal Republic of Germany.
authors.forename: J
authors.initials: J
authors.lastname: Müller-Höcker
authors.forename: H
authors.initials: H
authors.lastname: Ibel
authors.forename: I
authors.initials: I
authors.lastname: Paetzke
authors.forename: T
authors.initials: T
authors.lastname: Deufel
authors.forename: W
authors.initials: W
authors.lastname: Endres
authors.forename: B
authors.initials: B
authors.lastname: Kadenbach
authors.forename: J M
authors.initials: JM
authors.lastname: Gokel
authors.forename: G
authors.initials: G
authors.lastname: Hübner
mesh_terms: D009202:Cardiomyopathies / Q000150:complications / Q000201:enzymology / Q000473:pathology*; D002675:Child, Preschool; D030401:Cytochrome-c Oxidase Deficiency; D006801:Humans; D008297:Male; D008929:Mitochondria, Heart / Q000201:enzymology / Q000473:pathology*; D009135:Muscular Diseases / Q000150:complications / Q000201:enzymology / Q000473:pathology*; D009245:NADH Dehydrogenase / Q000172:deficiency
chemical_list: D009245:NADH Dehydrogenase