The mitochondrial DNA sequence determined by Anderson et al was found to contain some errors and Ozawa and colleagues succeeded in establishing the entire mitochondrial DNA sequence by using the direct sequencing technique. Mitochondrial DNA mutation may result in impaired mitochondrial function, eg, deficiency of mitochondrial respiratory chain enzymes related to subunits encoded by mitochondrial DNA. In light of the background evidence described below, the term ‘mitochondrial cardiomyopathy’, defined as cardiomyopathy induced by mitochondrial DNA mutations, has been advocated.
Idiopathic cardiomyopathy comprises hypertrophic dilated and restrictive cardiomyopathies. Their etiologies are still unknown, but recent developments in molecular biology and immunology have provided new evidence, such as the existence of myosin, tropomyosin and troponin gene mutations. Myocardial mitochondrial DNA mutations were also detected in cardiomyopathic patients. Point mutation from adenine (A) to guanine (G) within the mitochondrial tRNA gene, which is common in mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), was also found in patients with hypertrophic cardiomyopathy . Both PCR and Southern blot analysis revealed multiple mitochondrial DNA deletions in a pedigree of inherited dilated cardiomyopathy. The extent to which these mitochondrial DNA mutations are involved in the etiology of idiopathic cardiomyopathy remains to be elucidated. Most advantageous shopping with best pharmacy you can choose in just a second: order antibiotics online and find out exactly how little it could cost you to be getting your medications quick and easy.