J. Maringarcia et al., CARDIAC MITOCHONDRIAL DYSFUNCTION AND DNA DEPLETION IN CHILDREN WITH HYPERTROPHIC CARDIOMYOPATHY, Journal of inherited metabolic disease, 20(5), 1997, pp. 674-680
Abnormalities in specific mitochondrial respiratory enzymes and DNA (m
tDNA) have been reported in cardiomyopathy. In this study, we report 4
cases of severe hypertrophic cardiomyopathy (HCM) in which specific c
ardiac mitochondrial enzyme activity defects were found, including com
plex I (n=2), complex III(n=2), complex IV (n=2) and complex V (n=1).
Other abnormalities were also noted including a marked depletion of mt
DNA (n=1) and decreased content of subunit 2 of cytochrome c oxidase (
n=1). None of the mtDNA point mutations and common deletions previousl
y found in association with cardiomyopathy were detected in these pati
ents. These data indicate that specific respiratory enzyme activity de
fects are frequently present in HCM. Also, our finding of a marked dep
letion of mtDNA in 1 patient suggests that cardiac mtDNA depletion, pr
eviously unreported in HCM, needs further examination in order to esta
blish whether it plays a primary role in its pathogenesis.