Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) mostly occur in children. The point mutation A3243G of mitochondrial DNA (mtDNA) may work as a specific bio-marker for mitochondrial disorders. The related clinical features, however, may vary among individuals. This study therefore investigated the relation between MELAS clinical features and point mutation A324...

OBJECTIVES To further characterize mtDNA defects associated with autistic features, especially the A3243G mtDNA mutation and mtDNA depletion.Study design Five patients with autistic spectrum disorders and family histories of mitochondrial DNA diseases were studied. We performed mtDNA analysis in all patients and magnetic resonance spectroscopy in three. RESULTS Three patients manifested isola...

OBJECTIVES To determine (1) detailed retinal and audiological features of probands harboring the A3243G mitochondrial DNA mutation (m.3243A>G) and their asymptomatic maternal relatives, (2) intrafamilial and interfamilial phenotypic variability, and (3) the presence of other systemic features. METHODS Seven probands harboring the A3243G mitochondrial DNA mutation and 36 asymptomatic maternal ...

Mutant mitochondrial (mt) DNA variants are related to human disease and have been investigated using cytoplasmic hybrid (cybrid) cells generated from human tumor cells in which mutant mt maintenance depends on the cell line. It is, however, unclear whether human intercellular fusion of non-tumorous cells influences the maintenance of disease-related mutant mt. A preliminary experiment of cell-c...

Fine scale meiotic recombination maps have uncovered a large amount of variation in crossover rate across the genomes of many species, and such variation in mammalian and yeast genomes is concentrated to <5kb regions of highly elevated recombination rates (10-100x the background rate) called "hotspots." Drosophila exhibit substantial recombination rate heterogeneity across their genome, but evi...

BACKGROUND Mitochondrial DNA (mtDNA) A3243G mutation is one of the major causative factors of mitochondrial diabetes mellitus. We found that tissues from 2 of 142 diabetes mellitus patients showed extremely high levels of the mutation. OBJECTIVE To investigate the level of the mutation in each tissue and to find the relationship between the mutation level and clinical features of the patients...

The mitochondrial A3243G tRNALeu(UUR) mutation associated with a variety of mitochondrial disorders results in a severe respiratory deficiency, an increase in reactive oxygen species (ROS) production and activities of anti-oxidative enzyme in vitro. However, the phenotypic implications of this mutation have not been described in vivo. Here, mitochondria carrying A3243G transition from the perip...

Many patients with inherited mitochondrial encephalopathies have one of two pathogenic mutations of mitochondrial DNA (mtDNA): A3243G or A8344G. Individuals who harbour these mutations carry both mutant and wild-type alleles within each cell (heteroplasmy). Despite clear evidence of a direct relationship between the level of mutation and mitochondrial respiratory chain function in vitro, it has...