Author/Editor		Arbustini, Eloisa; Morbini, Patrizia; Diegoli, Marta
Title		Mitochondrial DNA mutations in cardiomyopathies
Type		članek
Source		In: Pajer Z, Štiblar-Martinčič D, editors. International symposium on cardiovascular diseases. Proceedings of the 29th memorial meeting devoted to prof. dr. Janez Plečnik; 1998 Dec 3-5; Ljubljana. Ljubljana: Medical faculty, Institute of histology and embryology,
Publication year		1998
Volume		str. 403-11
Language		eng
Abstract		Mitochondria are intracellular organelles found in all mammalian cells, that are responsible for the bulk of energy production within cells by oxidative phosphorilation. The field of mitochondrial DNA-related pathology was started in 1988, with the report of mtDNA deletions in spontaneous encephalomyopathies and of mtDNA missense mutations in Leber's Hereditary Optic Neuropathy. THe human mitochondrial genome is a 16.569bp circle of double stranded DNA. MtDNA contains 37 genes: 22 transfer RNA genes, 2 ribosomal RNAs, and 13 polypeptide coding genes. Each mitochondrion contains 5 to 10 DNA molecules. Mutations in mtDNA have been described in several multisystem disorders (most of them involving the heart), and in isolated cardiomyopathies, both hypertrophic and dilated. After sporadic reports of mtDNA mutations in cardiomyopathy patients, recent large scale investigations have demonstrated the presence of mtDNA defevts in a small, but significant proportionof patients with dilated cardiomyopathy, and ultrastructural mitochondrial abnormalities. In affected hearts mtDNA deletions of uncertain significance may occur; point mutations in the mtDNA have often been reported as associated with cardiomyopathies. Point mutations may afect protein-conding mt genes, tRNA, and rRNA. In order to attribute a pathologic significance to mitochondrial point mutations, the mutation must have involved a nucleotide that is highly conserved throughout evolution, must segregate with the phenotype, an must be heteroplasmic. Since a large part of mitochondrial enzyme subunits are encoded by nuclar genes, related disorders are expected to be relevant as well. Recent experimental studies have started to elucidate the nuclear gene defects that may be involved in mitochonrdrial diseases.(abstract truncated at 2000 characters)
Descriptors		MITOCHONDRIAL MYOPATHIES CARDIOMYOPATHY, CONGESTIVE CARDIOMYOPATHY, HYPERTROPHIC DNA, MITOCHONDRIAL DNA MUTATIONAL ANALYSIS POINT MUTATION GENETIC COUNSELING