• Sorting Linear Genomes with Rearrangements and Indels. (uni-bielefeld.de)
  • About 2000 completely sequenced mitochondrial genomes are available from the NCBI RefSeq data base together with manually curated annotations of their protein-coding genes, rRNAs, and tRNAs. (scienceopen.com)
  • We present an in silico approach for the reconstruction of complete mitochondrial genomes of non-model organisms directly from next-generation sequencing (NGS) data-mitochondrial baiting and iterative mapping (MITObim). (scienceopen.com)
  • The method is straightforward even if only (i) distantly related mitochondrial genomes or (ii) mitochondrial barcode sequences are available as starting-reference sequences or seeds, respectively. (scienceopen.com)
  • The approach overcomes the limitations of traditional strategies for obtaining mitochondrial genomes for species with little or no mitochondrial sequence information at hand and represents a fast and highly efficient in silico alternative to laborious conventional strategies relying on initial long-range PCR. (scienceopen.com)
  • The First Five Mitochondrial Genomes for the Family Nidulariaceae Reveal Novel Gene Rearrangements, Intron Dynamics, and Phylogeny of Agaricales . (bvsalud.org)
  • Here, we extend the recently described Genome BLAST Distance Phylogeny (GBDP) strategy to compute phylogenetic trees from all completely sequenced plastid genomes currently available and from a selection of mitochondrial genomes representing the major eukaryotic lineages. (biomedcentral.com)
  • Our results indicate that, at this taxonomic level, plastid genomes are much more valuable for inferring phylogenies than are mitochondrial genomes, and that distances based on breakpoints are of little use. (biomedcentral.com)
  • Nowadays, an increasing number of completely sequenced genomes are available and a growing field of phylogenetic research deals with the question of how to infer reliable phylogenies from this large amount of data to overcome the limitations of single-gene phylogenies. (biomedcentral.com)
  • A relatively obvious approach to phylogenetic analysis of whole genomes is to extract as many genes as possible from the genome sequences, create a multiple sequence alignment from each of the genes and to concatenate all alignments. (biomedcentral.com)
  • In view to find putative mitochondrial genes in alternative reading frames on both coding and "presupposed" non-coding strands, numerous complete mtDNA genomes have been analyzed. (biomedcentral.com)
  • However, the evolution and structure of mitochondrial genomes (mitogenomes) remain unclear in the Rosaceae family. (biomedcentral.com)
  • To develop molecular identification tools for Hydroides, the entire mitochondrial genomes of eight Hydroides species were sequenced by next-generation sequencing and the resultant reference sequences were used to design new taxon-specific COI primers. (edu.au)
  • Analyses of mitochondrial genomes of Hydroides showed a substantial rearrangement in gene order and numerous rarely reported large intergenic regions when compared with genomes of other known polychaetes. (edu.au)
  • Our understanding of plastid transcriptomes is limited to a few model plants whose plastid genomes (plastomes) have a highly conserved gene order. (biomedcentral.com)
  • Plastid genomes (plastomes) of land plants are highly conserved in their gene content and order. (biomedcentral.com)
  • These data were further used to predict all possible rearrangements between IS element copies present in Bordetella genomes, revealing that only a subset is observed among circulating strains. (cdc.gov)
  • Mitochondrial DNA (mtDNA) is DNA that is located in mitochondria. (dadamo.com)
  • This genetic material is known as mitochondrial DNA or mtDNA. (medlineplus.gov)
  • Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive multisystem disorder associated with depletion, multiple deletions and site-specific point mutations of mitochondrial DNA (mtDNA). (nih.gov)
  • The alterations of pyrimidine nucleoside metabolism are hypothesized to cause imbalances of mitochondrial nucleotide pools that, in turn, may cause somatic alterations of mtDNA. (nih.gov)
  • While direct repeats and imperfectly homologous sequences appear to mediate the formation of mtDNA deletions, the nicotinamide adenine dinucleotide dehydrogenase 5 gene is a hot-spot for these rearrangements. (nih.gov)
  • These subcellular organelles contain a genome that differs from the nuclear genome and is referred to as mitochondrial DNA (mtDNA). (biomedcentral.com)
  • These essential subcellular organelles contain mitochondrial DNA (mtDNA), which is an extrachromosomal genetic element. (biomedcentral.com)
  • A rapid diagnostic 'mulitplex' one-step polymerase chain reaction protocol (RD-PCR) was developed using cytochrome oxidase subunit 1 (COX1) mitochondrial DNA (mtDNA) to discriminate between S. haematobium and S. bovis. (imperial.ac.uk)
  • A number of maternally inherited mitochondrial diseases with distinct clinical phenotypes have been associated with point mutations in mtDNA, all of which result in neurologic or neuromuscular disorders. (celljournal.org)
  • Several studies showed that mutations in the tRNA genes of mtDNA could cause mitochondrial disease due to the decreased synthesis of mitochondrial DNA coded proteins. (celljournal.org)
  • A patient having clinical, biochemical, and histochemical abnormalities compatible with mitochondrial disease but without rearrangements in her mtDNA, was subjected to study for point mutations in the mitochondrial tRNA genes. (celljournal.org)
  • A New Point Mutation In MtDNA TRNA Ser (UCN) Gene In A Cardiomyopathic Patient', Cell Journal (Yakhteh) , 1(1), pp. 19-26. (celljournal.org)
  • Alternatively, diagnosis may be established by muscle biopsy with histochemistry and mitochondrial DNA (mtDNA) analysis for major rearrangements. (medscape.com)
  • In addition, mitochondrial DNA (mtDNA) encodes 2 ribosomal RNA genes and 22 transfer RNA (tRNA) genes necessary for the intramitochondrial synthesis of these 13 polypeptides. (medscape.com)
  • Located within the mitochondrial matrix, and lacking the efficient repair mechanisms available to nuclear DNA, mtDNA has a relatively high rate of mutation. (medscape.com)
  • Mutations of mitochondrial DNA can lead to a number of illnesses including exercise intolerance and Kearns-Sayre syndrome (KSS), which causes a person to lose full function of their heart, eye, and muscle movements. (dadamo.com)
  • As people age, mitochondrial DNA accumulates damaging mutations, including deletions and other changes. (medlineplus.gov)
  • Mutations in at least three mitochondrial genes can cause cytochrome c oxidase deficiency, which is a condition that can affect several parts of the body, including the muscles used for movement (skeletal muscles), the heart, the brain, or the liver. (medlineplus.gov)
  • We hypothesize that there might be at least three types of autism susceptibility genes/mutations that can be (i) specific to an individual patient or family, (ii) in a genetically isolated sub-population and (iii) a common factor shared amongst different populations. (neurotransmitter.net)
  • The genes/mutations could act alone or interact with other genetic and/or epigenetic or environmental factors, causing autism or related disorders. (neurotransmitter.net)
  • A compound heterozygous mutation of the alkaline phosphatase ALPL gene causes hypophosphatasia in a Han Chinese language household Hypophosphatasia (HPP) is a uncommon hereditary systemic illness that's characterised by faulty bone and/or dental mineralization, and is brought on by mutations within the alkaline phosphatase gene (ALPL). (sourui-koza.com)
  • SCID results from mutations in any of more than 15 known genes. (medscape.com)
  • However many proteins found in the mitochondria are encoded by nuclear DNA: some, if not most, are thought to have been originally part of the mitochondrial DNA but have since been transferred to the nucleus during evolution. (dadamo.com)
  • The mitochondrial genes associated with cytochrome c oxidase deficiency provide instructions for making proteins that are part of a large enzyme group (complex) called cytochrome c oxidase (also known as complex IV). (medlineplus.gov)
  • Immunohistochemical analyses using an anti-Gau monoclonal antibody revealed strict co-localization of Gau proteins and a mitochondrial marker. (biomedcentral.com)
  • Typical triploblastic animal mtDNAs contain genes that encode the large and small subunit ribosomal RNAs, 22 transfer RNAs (tRNAs), and 13 proteins that are all components of the oxidative phosphorylation process: ATPase subunits 6 and 8 (ATP6 and 8), cytochrome b (Cyt b), cytochrome c oxidase subunits 1-3 (Cox1-3) and NADH dehydrogenase subunits 1-6 and 4L (ND1-6 and 4L). (biomedcentral.com)
  • Two genes encoding putative internalin proteins were chosen for further study. (omictools.com)
  • We sequenced the complete mt genome of W. compar and conducted phylogenetic analyses using concatenated coding sequences of 12 protein-coding genes (PCGs) by maximum likelihood and Bayesian inference. (nature.com)
  • We assembled a complete mitogenome of the intertidal spider Desis jiaxiangi and performed comparative mitochondrial analyses of data set comprising of Desis jiaxiangi and other 45 previously published spider mitogenome sequences, including that of Argyroneta aquatica . (biomedcentral.com)
  • In addition, using sequences of three mitochondrial genes, the phylogenetic relationships between every sample with a known karyotype were determined, which revealed significant nucleotide divergence among the karyomorphs. (scielo.br)
  • Partial mitochondrial16S rRNA gene sequences from the infected flies matched sequences derived from black fly larvae cytotaxonomically identified as Simulium tribulatum . (cdc.gov)
  • This is the currently accepted taxonomy (Bronner & Jenkins 2005), though some minor changes may result when a phylogeny based on nuclear and mitochondrial gene sequences (currently being undertaken at the University of Pretoria by members of the Afrotheria Specialist Group) becomes available. (aviandesign.net)
  • Comparative genomic analysis of T . equi revealed the phylogenetic positioning relative to seven apicomplexan parasites using deduced amino acid sequences from 150 genes placed it as a sister taxon to Theileria spp . (biomedcentral.com)
  • Summary: Comparative genomics remains a pivotal strategy to study the evolution of gene organization, and this primacy is reinforced by the growing number of full genome sequences available in public repositories. (omictools.com)
  • We observed a distinction in the repeat lengths of the circumsporozoite protein (CSP) gene sequences between P. brasilianum and P. malariae. (cdc.gov)
  • We studied chromosome structure in complete genome sequences from 167 Bordetella species isolates, as well as 469 B. pertussis isolates, to gain a generalized understanding of rearrangement patterns among these related pathogens. (cdc.gov)
  • The complete mt genome is 14,373 bp in size and comprises 36 genes, including 12 protein-coding, two rRNA and 22 tRNA genes. (nature.com)
  • All the 22 typical animal tRNA genes are found in M. sexmaculata mitogenome, and most of the tRNAs could be folded into the classic cloverleaf secondary structure. (scienceopen.com)
  • After a long period of evolution, the genetic composition of mt in most metazoans is now present consistently, suggesting that mt genes are important for maintaining the basic functions of mt 9 . (nature.com)
  • Changes in mitochondrial DNA are among the best-studied genetic factors associated with age-related hearing loss. (medlineplus.gov)
  • Some of the genetic changes alter single DNA building blocks (nucleotides), whereas others rearrange larger segments of mitochondrial DNA. (medlineplus.gov)
  • Identification of a disease-causing variant may assist with diagnosis, prognosis, clinical management, familial screening, and genetic counseling for nuclear mitochondrial disease. (testcatalog.org)
  • Moreover, this strengthens evidence for mitochondrial genes coded according to an overlapping genetic code. (biomedcentral.com)
  • Researchers from The Hospital for Sick Children (SickKids) have uncovered new genes and genetic changes associated with autism spectrum disorder (ASD) in the largest autism whole genome sequencing analysis to date, providing better understanding into the 'genomic architecture' that underlies this disorder. (medicalxpress.com)
  • The team found 134 genes linked with ASD and discovered a range of genetic changes , most notably gene copy number variations (CNVs), likely to be associated with autism, including ASD-associated rare variants in about 14 percent of participants with autism. (medicalxpress.com)
  • The first stage involved identifying, in unrelated subjects showing linkage to 2q24-q33, genetic variants in exons and flanking sequence within candidate genes and comparing the frequency of the variants between autistic and unrelated nonautistic subjects. (neurotransmitter.net)
  • Recognition of a single-gene disorder as causal for a patient's 'multiple sclerosis-like' phenotype is critically important for accurate direction of patient management, and evokes broader genetic counselling implications for affected families. (medscape.com)
  • The mitochondrial genome encodes the genetic information for the 13 polypeptide subunits essential for the process of oxidative phosphorylation. (medscape.com)
  • However, similar genetic rearrangements in this syndrome may determine variable phenotypic effects, most likely as a consequence of allelic variation in the homologous 4p region. (medscape.com)
  • With the advances in BMT and gene therapy, patients now have a better likelihood of developing a functional immune system in a previously lethal genetic disease. (medscape.com)
  • Surprisingly, Pirata subpiraticus , Hypochilus thorelli , and Argyroneta aquatica each had a higher Ka/Ks value in the 13 PCGs dataset among 46 taxa with complete mitogenomes, and these three species also showed positive selection signal in the nd6 gene. (biomedcentral.com)
  • As a result, reactive oxygen species easily damage mitochondrial DNA, causing cells to malfunction and ultimately to die. (medlineplus.gov)
  • Gene Ontology analysis in both species, for the genes that exhibited inverse transcriptomic coordination during aging pointed to alterations in the perception of smell, a known impairment occurring during aging. (nsf.gov)
  • Sequence variations in the mitochondrial cytochrome-b (Cytb) gene and the sex-determining gene of Y chromosome (Sry), which show maternal and paternal inheritance, respectively, were examined in 2 species of Japanese voles of the genus Eothenomys (Arvicolinae), E. andersoni and E. smithii, to elucidate phylogenies within and between species. (cgrb.org)
  • Sry gene variation, in contrast, was species specific and was polymorphic in E. andersoni with substantial geographic distribution, but it was monomorphic in E. smithii, suggesting a recent geographic expansion of E. smithii eastward. (cgrb.org)
  • We attribute the complicated population genetics to topographic complexity of the Japanese islands and suggest that rearrangement of species was associated with climatic changes during the Quaternary glaciation on the basis of an assumption of divergence time among several murine rodents. (cgrb.org)
  • Molecular tools, especially cytochrome c oxidase subunit I (COI) barcoding that have proven useful for species delimitation and discovery in eukaryotes, have not been widely used in Hydroides due to the high amplification failure rate of the COI gene. (edu.au)
  • Combined data of three gene markers (18S, ITS, cytochrome b) and morphological data were used to resolve the taxonomic status of another widely distributed species, Hydroides brachyacantha. (edu.au)
  • We demonstrate that the expression of plastid coding genes is strongly functionally dependent among conifer species. (biomedcentral.com)
  • 240 copies of IS481, IS elements appear less numerous in other species and yield less chromosome structural diversity through rearrangement. (cdc.gov)
  • Therefore, while it appears that rearrangement occurs less frequently in other species than in B. pertussis, these clinically relevant respiratory pathogens likely experience similar mutation of gene order. (cdc.gov)
  • The chromosome of B. pertussis has previously been shown to exhibit considerable structural rearrangement, but insufficient data have prevented comparable investigation in related species. (cdc.gov)
  • This putative gene has been named gau for g ene a ntisense u biquitous in mtDNAs. (biomedcentral.com)
  • T . equi has lost the putative genes for host cell transformation, or the genes were acquired by T . parva and T . annulata after divergence from T . equi . (biomedcentral.com)
  • Our selection analyses detected a positive selection signal in the nd4 gene of the aquatic branch comprising both Desis jiaxiangi and Argyroneta aquatica . (biomedcentral.com)
  • Also, the analyses indicate that chromosomal rearrangements occurred independently within the distinct lineages of S . marmoratus complex, which resulted in the appearance of distinct karyotypic variants in a non-linear fashion related to diploid numbers and in the appearance of similar non-homologous chromosomes. (scielo.br)
  • Understanding the forces that drive the evolution of the mitochondrial genome (mitogenome) provides crucial information, as this evolution is affected by a range of factors that in turn influence the information content of the genome. (biomedcentral.com)
  • The mitogenome of M. sexmaculata is a circular molecule of 16,663 bp with 75.00% AT content, containing 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs, and one non-coding control region. (scienceopen.com)
  • The mitogenome is 16,401 bp in length and consisted of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region. (pensoft.net)
  • overall, an over 600-fold variance in mitogenome rearrangement rates has been observed among seed plants [ 8 ]. (biomedcentral.com)
  • A nested PCR based on the sequence of the cytochrome oxidase subunit 1 gene of the parasite was developed and used to screen Simulium black flies collected from southern California for O. lupi DNA. (cdc.gov)
  • 16S and 12S), which are essential for various mitochondrial functions [ 9 ]. (biomedcentral.com)
  • This group includes lysosomal storage disorders, various mitochondrial diseases, other neurometabolic disorders, and several other miscellaneous disorders. (medscape.com)
  • Most phenotypic manifestations in this syndrome reflect a contiguous gene syndrome, leading to a phenotypic map of chromosome arm 4p. (medscape.com)
  • Whooping cough (pertussis), primarily caused by Bordetella pertussis, has resurged in the United States, and circulating strains exhibit considerable chromosome structural fluidity in the form of rearrangement and deletion. (cdc.gov)
  • The remaining genes provide instructions for making molecules called transfer RNA (tRNA) and ribosomal RNA (rRNA), which are chemical cousins of DNA. (medlineplus.gov)
  • Deletion of either gene (GBAA0552 or GBAA1340) resulted in attenuation in a murine model of infection. (omictools.com)
  • Dias Vieira Braga M, Machado R, Ribeiro LC, Stoye J. Genomic distance under gene substitutions. (uni-bielefeld.de)
  • Therefore comparative genomic analysis of T . equi was undertaken to: 1) identify genes contributing to immune evasion and persistence in equid hosts, 2) identify genes involved in PBMC infection biology and 3) define the phylogenetic position of T . equi relative to sequenced apicomplexan parasites. (biomedcentral.com)
  • Consequently, little is known about how gene expression changes in response to genomic rearrangements in plastids. (biomedcentral.com)
  • Difficulties with this approach may arise if orthologous genes cannot be identified with certainty or if the combined sequence length is still too small to give well-resolved trees. (biomedcentral.com)
  • This hypothesis could be tested by purifying the gau gene product and determining its sequence. (biomedcentral.com)
  • Furthermore, P. brasilianum had 4864 (82.1%) genes that share 80% or higher sequence similarity with 4970 (75.5%) P. malariae genes. (cdc.gov)
  • Finally, the integration of both molecular cytogenetic and phylogenetic approaches allowed the determination of specific chromosomes possibly involved in rearrangements and a better understanding about the evolutionary processes involved in the differentiation of Synbranchus genus. (scielo.br)
  • The genome is 31.4Mb in size and comprises 14 chromosomes, the mitochondrial genome, the apicoplast genome, and 29 unplaced contigs. (cdc.gov)
  • Further information on the laboratory's involvement in mitochondrial genetics research is available on the Oxford research page of the NHS Rare Mitochondrial Disorders Service website . (ouh.nhs.uk)
  • The existence of separate mitochondrial DNA suggests that, at one point, mitochondria were separate entities from their current host cells. (dadamo.com)
  • A positionally conserved ORF has been found on the complementary strand of the cox1 genes of both eukaryotic mitochondria (protist, plant, fungal and animal) and alpha-proteobacteria. (biomedcentral.com)
  • This review emphasizes the potential of analysing chromosomal rearrangements as a means to rapidly define candidate disease loci for further investigation. (neurotransmitter.net)
  • The diagnostic workup for a mitochondrial disorder may include testing to demonstrate elevations of the lactate-to-pyruvate ratio and an elevated growth differentiation factor 15 concentration. (testcatalog.org)
  • Here we review single gene disorders that have the potential to mimic multiple sclerosis, provide an overview of clinical and investigational characteristics of each disorder, and present guidelines for when clinicians should suspect an underlying heritable disorder that requires diagnostic confirmation in a patient with a definite or probable diagnosis of multiple sclerosis. (medscape.com)
  • Inoculation with a high dose strains of LMP1 transgenic mice vide a powerful tool in mechanistic of EBV caused a B-cell lymphopro- were established that express LMP1 studies on the role of individual viral liferative disorder in these mice, under the control of the immunoglob- genes in cancer. (who.int)
  • Despite a disparity in gene content, all mtDNAs encode at least two components of the mitochondrial electron transport chain, including cytochrome c oxidase I (Cox1). (biomedcentral.com)
  • This search has led to the observation of an unknown, positionally conserved open reading frame (ORF) on the complementary strand of eukaryotic cox1 genes. (biomedcentral.com)
  • Among the genes that exhibited the most pronounced inversion in their coordination profiles during aging was THBS4, that encodes for thrombospondin-4, a protein that was recently identified as rejuvenation factor in mice. (nsf.gov)
  • The number of mitochondrial protein genes is believed to vary from 3 to 67, while the tRNA gene content varies from 0 to 27 [ 2 ]. (biomedcentral.com)
  • Comparative analysis of six genera from the Amygdaloideae and five from the Rosoideae subfamilies of Rosaceae revealed that three protein-coding genes were absent from the mitogenomes of five Rosoideae genera. (biomedcentral.com)
  • Results of kinase inhibitors on viral RNA replication The immunofluorescence detection of viral capsid protein presented a qualitative indication of no matter whether a given kinase inhibitor affected the initiation of the infection processes leading to viral gene expression. (mirnaassay.com)
  • The fact that mitochondrial DNA is maternally inherited enables researchers to trace uterine lineage far back in time. (dadamo.com)
  • The role of the maternally inherited mitochondrial DNA was also examined in the study and found to account for two percent of autism. (medicalxpress.com)
  • This is accomplished in humans by sequencing one or more of the hypervariable control regions (HVR1 or HVR2) of the mitochondrial DNA. (dadamo.com)
  • In humans, mitochondrial DNA spans about 16,500 DNA building blocks (base pairs), representing a small fraction of the total DNA in cells. (medlineplus.gov)
  • Two single nucleotide polymorphisms (SNPs) that showed evidence for divergent distribution between autistic and nonautistic subjects were identified, both within SLC25A12, a gene encoding the mitochondrial aspartate/glutamate carrier (AGC1). (neurotransmitter.net)
  • Abstract Background Genes that belong to the same network are frequently co-expressed, but collectively, how the coordination of the whole transcriptome is perturbed during aging remains unclear. (nsf.gov)
  • These variant types include complex rearrangements of DNA, as well as tandem repeat expansions, a finding supported by recent SickKids research on the link between autism and DNA segments that are repeated many times. (medicalxpress.com)
  • Conclusions There sults suggest that aging is associated with more stringent retention of expression profiles for some genes and more abrupt changes in others, while more subtle but widespread changes in gene expression appear protective. (nsf.gov)
  • CONCLUSIONS: A strong association of autism with SNPs within the SLC25A12 gene was demonstrated. (neurotransmitter.net)
  • This study aimed to determine the complete mitochondrial (mt) genome of W. compar and reconstruct its phylogenetic relationship with other nematodes. (nature.com)
  • We sequenced the complete mitochondrial genome of Menochilus sexmaculata (Fabricius, 1781) and compared it with that of other insects. (scienceopen.com)
  • In the present study, the complete mitochondrial genome of P. flavomaculatus was sequenced and analyzed. (pensoft.net)
  • Please complete a mitochondrial pre-referral form to accompany samples (see referral forms ). (ouh.nhs.uk)
  • Studies of the gau ORF will shed light on the origin of novel genes and their functions in organelles and could also have medical implications for human diseases that are caused by mitochondrial dysfunction. (biomedcentral.com)
  • Phylogenetics and biogeography of the globally important calcareous tubeworm genus Hydroides Gunnerus, 1768 (Serpulidae, Polychaeta) inferred with multiple gene markers -- Chapter 9. (edu.au)
  • Our findings shed light in the mode of the transcriptional changes occurring in the brain during aging and suggest that strategies aiming to broader but more modest changes in gene expression may be preferrable to correct aging-associated deregulation in gene expression. (nsf.gov)
  • In flies, as in mammals, the aging eye undergoes changes in gene expression that correlate with declining visual function and increased risk of retinal degeneration. (nsf.gov)
  • Genome-wide transcript analysis showed that B. anthracis undergoes considerable changes in gene expression during growth in iron-depleted media, including the regulation of known and candidate virulence factors. (omictools.com)
  • Targeted testing for familial variants (also called site-specific or known variants testing) is available for the genes on this panel. (testcatalog.org)
  • In P. leucopus, alterations in genes related to cholesterol metabolism were also identified. (nsf.gov)
  • The following chromosomal conditions are associated with changes in the structure or number of copies of mitochondrial dna. (medlineplus.gov)
  • The mitochondrial genome is a 16569 base-pair closed circular loop of double-stranded DNA found in multiple copies within the mitochondrial matrix. (medscape.com)
  • Some cases of cyclic vomiting syndrome, particularly those that begin in childhood, may be related to changes in mitochondrial DNA. (medlineplus.gov)