Differential diagnosis of fatal and benign cytochrome c oxidase-deficient myopathies of infancy: an immunohistochemical approach.
To differentiate the 2 major myopathies of infancy due to cytochrome c oxidase (COX) deficiency, we studied muscle biopsies from 4 patients with fatal myopathy and 4 with benign myopathy using biochemical, histochemical, and immunohistochemical techniques. Immunohistochemistry with antibodies directed against individual subunits of COX differentiated the 2 phenotypes: the fatal infantile myopathy was characterized by absence of the nuclear DNA (nDNA)-encoded subunit VIIa,b of COX, while in the benign myopathy both VIIa,b and the mitochondrial DNA (mtDNA)-encoded subunit II were absent. Early differential diagnosis between fatal and benign COX-deficient myopathies is of critical importance for prognosis and management of these infants, because the benign form is initially life-threatening but ultimately reversible.
Tritschler
H J
HJ
Department of Neurology, Columbia University, College of Physicians and Surgeons, New York, NY 10032.
Bonilla
E
E
Lombes
A
A
Andreetta
F
F
Servidei
S
S
Schneyder
B
B
Miranda
A F
AF
Schon
E A
EA
Kadenbach
B
B
DiMauro
S
S
D001706:Biopsy; D030401:Cytochrome-c Oxidase Deficiency; D003937:Diagnosis, Differential; D003576:Electron Transport Complex IV / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007231:Infant, Newborn; D009135:Muscular Diseases / Q000201:enzymology* / Q000401:mortality / Q000473:pathology
D003576:Electron Transport Complex IV