Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the fam...

We determined the nucleotide sequences of junctional regions associated with large deletions of mitochondrial DNA found in four unrelated individuals with a phenotype of chronic progressive external ophthalmoplegia. In each patient, the deletion breakpoint occurred within a directly repeated sequence of 13-18 base pairs, present in different regions of the normal mitochondrial genome-separated ...

The D-loop region is a hot spot for mitochondrial DNA (mtDNA) alterations, containing two hypervariable segments, HVS-I and HVS-II. In order to identify polymorphic sites and potential genetic background accounting for Hypertrophic CardioMyopathy (HCM) disease, the complete non-coding region of mtDNA from 31 unrelated HCM patients and 45 normal controls were sequenced. The sequences were aligne...

Previous work by our group and others has demonstrated that mitochondrial DNA (mtDNA) deletions may be useful as a biomarker of cumulative ultraviolet radiation exposure in human skin (Birch-Machin, 2000). Of particular importance is the incidence of various mtDNA deletions, including the 4977 bp ‘‘common’’ deletion, which has been strongly associated with increased sun exposure in human skin (...

In the Saccharomyces cerevisiae strains used for genome sequencing and functional analysis, the mitochondrial DNA replicase Mip1p contains a single nucleotide polymorphism changing the strictly conserved threonine 661 to alanine. This substitution is responsible for the increased rate of mitochondrial DNA point mutations and deletions in these strains.

Clonal expansion of mtDNA deletions compromises mitochondrial function in human disease and aging, but how deleterious mtDNA genomes propagate has remained unclear. In this issue (Gitschlag et al., 2016) and in a recent Nature publication, C. elegans studies implicate the mitochondrial unfolded protein response (UPR(mt)) and offer mechanistic insights into this process.

BACKGROUND Reactive oxygen species (ROS) play a major role in causing injury in ischemia-reperfusion (I/R). Mitochondrial DNA (mtDNA) is particularly vulnerable to oxidative damage. We propose that increased mitochondrial ROS production is likely to damage mtDNA, causing further injury to mitochondria, and postconditioning (POC) may ameliorate kidney I/R injury by mitigating mitochondrial damag...

BACKGROUND Chronic progressive external ophthalmoplegia (CPEO) is a classical mitochondrial ocular disorder characterised by bilateral progressive ptosis and ophthalmoplegia. These ocular features can develop either in isolation or in association with other prominent neurological deficits (CPEO+). Molecularly, CPEO can be classified into two distinct genetic subgroups depending on whether patie...