Mitochondrial Cardiomyopathy -⁠ Case Report

Overview

A male infant developed progressive neuromuscular disease, hypertrophic cardiomyopathy andbrain atrophy since the birth. Increased level of lactate with increased lactate/pyruvate ratiosuggested a disturbance in the mitochondrial energy metabolism. The activities of respiratorychain complexes III, IV and II + III, of pyruvate dehydrogenase complex and of citrate synthase inisolated muscle mitochondria were low in comparison with controls, with parallel decrease in thecontent of protein amount of respiratory chain complexes III and IV. No large scale deletions ofmitochondrial DNA (mtDNA) and mtDNA point mutations A3243G, A8344G or T8993G indicatingsyndromes MELAS, MERRF or NARP were detected. The boy died at the age of 7 weeks. Theautopsy revealed typical changes of mitochondrial cardiomyopathy-marked myocardial hypertrophy with muscle pallor, histological finding of diffuse fine granularity of the cytoplasm in theperinuclear regions, and ultrastructural findings of mitochondrial hyperplasia, enlargement (megamitochondria) and abnormal shape.

Key words:
mitochondrial metabolism -⁠ mitochondrial cardiomyopathy -⁠ congenital diseases