Mutations In Mitochondrial Genes Research Articles

Consequences of zygote injection and germline transfer of mutant human mitochondrial DNA in mice

Considerable evidence supports mutations in mitochondrial genes as the cause of maternally inherited diseases affecting tissues that rely primarily on oxidative energy metabolism, usually the nervous system, the heart, and skeletal muscles. Mitochondrial diseases are diverse, and animal models currently are limited. Here we introduced a mutant human mitochondrial gene responsible for Leber hereditary optic neuropathy (LHON) into the mouse germ line using fluorescence imaging for tissue-specific enrichment in the target retinal ganglion cells. A mitochondria-targeted adeno-associated virus (MTS-AAV) containing the mutant human NADH ubiquinone oxidoreductase subunit 4 (ND4) gene followed by mitochondrial-encoded mCherry was microinjected into zygotes. Female founders with mCherry fluorescence on ophthalmoscopy were backcrossed with normal males for eight generations. Mutant human ND4 DNA was 20% of mouse ND4 and did not integrate into the host genome. Translated human ND4 protein assembled into host respiratory complexes, decreasing respiratory chain function and increasing oxidative stress. Swelling of the optic nerve head was followed by progressive demise of ganglion cells and their axons, the hallmarks of human LHON. Early visual loss that began at 3 mo and progressed to blindness 8 mo after birth was reversed by intraocular injection of MTS-AAV expressing wild-type human ND4. The technology of introducing human mitochondrial genes into the mouse germ line has never been described, to our knowledge, and has implications not only for creating animal models recapitulating the counterpart human disorder but more importantly for reversing the adverse effects of the mutant gene using gene therapy to deliver the wild-type allele.

A novel mutation MT-COIII m.9267G>C and MT-COI m.5913G>A mutation in mitochondrial genes in a Tunisian family with maternally inherited diabetes and deafness (MIDD) associated with sever nephropathy

Mitochondrial diabetes (MD) is a heterogeneous disorder characterized by a chronic hyperglycemia, maternal transmission and its association with a bilateral hearing impairment. Several studies reported mutations in mitochondrial genes as potentially pathogenic for diabetes, since mitochondrial oxidative phosphorylation plays an important role in glucose-stimulated insulin secretion from beta cells. In the present report, we studied a Tunisian family with mitochondrial diabetes (MD) and deafness associated with nephropathy. The mutational analysis screening revealed the presence of a novel heteroplasmic mutation m.9276G > C in the mitochondrial COIII gene, detected in mtDNA extracted from leukocytes of a mother and her two daughters indicating that this mutation is maternally transmitted and suggest its implication in the observed phenotype. Bioinformatic tools showed that m.9267G > C mutation (p.A21 p ) is “deleterious” and it can modify the function and the stability of the MT-COIII protein by affecting the assembly of mitochondrial COX subunits and the translocation of protons then reducing the activity of the respective OXPHOS complexes of ATP synthesis. The nonsynonymous mutation (p.A21P) has not been reported before, it is the first mutation described in the COXIII gene which is related to insulin dependent mitochondrial diabetes and deafness and could be specific to the Tunisian population. The m.9267G > C mutation was present with a nonsynonymous inherited mitochondrial homoplasmic variation MT-COI m.5913 G > A (D4 N) responsible of high blood pressure, a clinical feature detected in all explored patients.

Impaired Mitochondrial Energy Production Causes Light-Induced Photoreceptor Degeneration Independent of Oxidative Stress.

Two insults often underlie a variety of eye diseases including glaucoma, optic atrophy, and retinal degeneration—defects in mitochondrial function and aberrant Rhodopsin trafficking. Although mitochondrial defects are often associated with oxidative stress, they have not been linked to Rhodopsin trafficking. In an unbiased forward genetic screen designed to isolate mutations that cause photoreceptor degeneration, we identified mutations in a nuclear-encoded mitochondrial gene, ppr, a homolog of human LRPPRC. We found that ppr is required for protection against light-induced degeneration. Its function is essential to maintain membrane depolarization of the photoreceptors upon repetitive light exposure, and an impaired phototransduction cascade in ppr mutants results in excessive Rhodopsin1 endocytosis. Moreover, loss of ppr results in a reduction in mitochondrial RNAs, reduced electron transport chain activity, and reduced ATP levels. Oxidative stress, however, is not induced. We propose that the reduced ATP level in ppr mutants underlies the phototransduction defect, leading to increased Rhodopsin1 endocytosis during light exposure, causing photoreceptor degeneration independent of oxidative stress. This hypothesis is bolstered by characterization of two other genes isolated in the screen, pyruvate dehydrogenase and citrate synthase. Their loss also causes a light-induced degeneration, excessive Rhodopsin1 endocytosis and reduced ATP without concurrent oxidative stress, unlike many other mutations in mitochondrial genes that are associated with elevated oxidative stress and light-independent photoreceptor demise.

Mitochondrial Morphology and Fundamental Parameters of the Mitochondrial Respiratory Chain Are Altered in Caenorhabditis elegans Strains Deficient in Mitochondrial Dynamics and Homeostasis Processes.

Mitochondrial dysfunction has been linked to myriad human diseases and toxicant exposures, highlighting the need for assays capable of rapidly assessing mitochondrial health in vivo. Here, using the Seahorse XFe24 Analyzer and the pharmacological inhibitors dicyclohexylcarbodiimide and oligomycin (ATP-synthase inhibitors), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (mitochondrial uncoupler) and sodium azide (cytochrome c oxidase inhibitor), we measured the fundamental parameters of mitochondrial respiratory chain function: basal oxygen consumption, ATP-linked respiration, maximal respiratory capacity, spare respiratory capacity and proton leak in the model organism Caenhorhabditis elegans. Since mutations in mitochondrial homeostasis genes cause mitochondrial dysfunction and have been linked to human disease, we measured mitochondrial respiratory function in mitochondrial fission (drp-1)-, fusion (fzo-1)-, mitophagy (pdr-1, pink-1)-, and electron transport chain complex III (isp-1)-deficient C. elegans. All showed altered function, but the nature of the alterations varied between the tested strains. We report increased basal oxygen consumption in drp-1; reduced maximal respiration in drp-1, fzo-1, and isp-1; reduced spare respiratory capacity in drp-1 and fzo-1; reduced proton leak in fzo-1 and isp-1; and increased proton leak in pink-1 nematodes. As mitochondrial morphology can play a role in mitochondrial energetics, we also quantified the mitochondrial aspect ratio for each mutant strain using a novel method, and for the first time report increased aspect ratios in pdr-1- and pink-1-deficient nematodes.

Yeast as a system for modeling mitochondrial disease mechanisms and discovering therapies.

ABSTRACTMitochondrial diseases are severe and largely untreatable. Owing to the many essential processes carried out by mitochondria and the complex cellular systems that support these processes, these diseases are diverse, pleiotropic, and challenging to study. Much of our current understanding of mitochondrial function and dysfunction comes from studies in the baker's yeast Saccharomyces cerevisiae. Because of its good fermenting capacity, S. cerevisiae can survive mutations that inactivate oxidative phosphorylation, has the ability to tolerate the complete loss of mitochondrial DNA (a property referred to as ‘petite-positivity’), and is amenable to mitochondrial and nuclear genome manipulation. These attributes make it an excellent model system for studying and resolving the molecular basis of numerous mitochondrial diseases. Here, we review the invaluable insights this model organism has yielded about diseases caused by mitochondrial dysfunction, which ranges from primary defects in oxidative phosphorylation to metabolic disorders, as well as dysfunctions in maintaining the genome or in the dynamics of mitochondria. Owing to the high level of functional conservation between yeast and human mitochondrial genes, several yeast species have been instrumental in revealing the molecular mechanisms of pathogenic human mitochondrial gene mutations. Importantly, such insights have pointed to potential therapeutic targets, as have genetic and chemical screens using yeast.

Mitochondrial respiratory dysfunction caused by a heteroplasmic mitochondrial DNA mutation blocks cellular reprogramming.

Mitochondrial dysfunction caused by pathogenic mutations in mitochondrial tRNA genes emerges only when mutant mitochondrial DNA (mtDNA) proportions exceed intrinsic pathogenic thresholds; however, little is known about the actual proportions of mutant mtDNA that can affect particular cellular lineage-determining processes. Here, we mainly focused on the effects of mitochondrial respiratory dysfunction caused by m.3243A>G heteroplasmy in MT-TL1 gene on cellular reprogramming. We found that generation of induced pluripotent stem cells (iPSCs) was drastically depressed only by high proportions of mutant mtDNA (≥ 90% m.3243A>G), and these proportions were strongly associated with the degree of induced mitochondrial respiratory dysfunction. Nevertheless, all established iPSCs, even those carrying ∼ 100% m.3243A>G, exhibited an embryonic stem cell-like pluripotent state. Therefore, our findings clearly demonstrate that loss of physiological integrity in mitochondria triggered by mutant mtDNA constitute a roadblock to cellular rejuvenation, but do not affect the maintenance of the pluripotent state.

Nonsense and missense mutation of mitochondrial ND6 gene promotes cell migration and invasion in human lung adenocarcinoma.

BackgroundPrevious study showed that mitochondrial ND6 (mitND6) gene missense mutation resulted in NADH dehydrogenase deficiency and was associated with tumor metastasis in several mouse tumor cell lines. In the present study, we investigated the possible role of mitND6 gene nonsense and missense mutations in the metastasis of human lung adenocarcinoma.MethodsThe presence of mitND6 gene mutations was screened by DNA sequencing of tumor tissues from 87 primary lung adenocarcinoma patients and the correlation of the mutations with the clinical features was analyzed. In addition, we constructed cytoplasmic hybrid cells with denucleared primary lung adenocarcinoma cell as the mitochondria donor and mitochondria depleted lung adenocarcinoma A549 cell as the nuclear donor. Using these cells, we studied the effects of mitND6 gene nonsense and missense mutations on cell migration and invasion through wounding healing and matrigel-coated transwell assay. The effects of mitND6 gene mutations on NADH dehydrogenase activity and ROS production were analyzed by spectrophotometry and flow cytometry.ResultsmitND6 gene nonsense and missense mutations were detected in 11 of 87 lung adenocarcinoma specimens and was correlated with the clinical features including age, pathological grade, tumor stage, lymph node metastasis and survival rate. Moreover, A549 cell containing mitND6 gene nonsense and missense mutation exhibited significantly lower activity of NADH dehydrogenase, higher level of ROS, higher capacity of cell migration and invasion, and higher pAKT and pERK1/ERK2 expression level than cells with the wild type mitND6 gene. In addition, NADH dehydrogenase inhibitor rotenone was found to significantly promote the migration and invasion of A549 cells.ConclusionsOur data suggest that mitND6 gene nonsense and missense mutation might promote cell migration and invasion in lung adenocarcinoma, probably by NADH dehydrogenase deficiency induced over-production of ROS.

Is the World of ART Ready for a Ménage à Trois?

A menage a trois (French for “household of three”) is a domestic arrangement in which three people having romantic and/or sexual relations with each other occupy the same household—From Wikipedia, the Free Encyclopedia Inherited diseases caused by mitochondrial gene (mtDNA) mutations affect at least one in 5000–10,000 children and are associated with severe clinical symptoms [1]. Mitochondrial disease mainly affects children, but is also common in adults due to deteriorating mitochondrial function with age [1]. Novel reproductive techniques designed to replace mutated mtDNA in oocytes or early embryos have been proposed to prevent transmission of disease from parents to their children [2, 3]. The aim is ultimately to prevent children from inheriting genetic diseases caused by mutations in DNA housed by their mitochondria—components of cells, which produce energy. Mitochondrial DNA (mtDNA) mutations are relatively a common cause of progressive disorders that can be severe or even life threatening [4]. There is currently no cure for these disorders; therefore, recent research has been focused on attempting to prevent the transmission of these maternally inherited mutations. These research techniques have been referred to with several terms, including “mitochondria replacement,” “mitochondrial manipulation,” “oocyte modification,” “three-person embryos,” “three-parent babies,” and “nuclear genome transfer.” The “mitochondria replacement” is a new approach that is being researched with the goal of allowing a woman who has mutations in her mtDNA to lessen the risk of passing on inherited mitochondrial disease to her child. The techniques being developed are variations on combining the nuclear DNA from an egg of an affected woman with the mtDNA of an unaffected woman’s egg. A resulting child would possess genes from three adults, and this altered genome would be passed on to succeeding generations.

Progressive supranuclear palsy: what do we know about it?

Progressive supranuclear palsy (PSP) is a progressive tauopathy characterized by supranuclear ophthalmoplegia, pseudobulbar palsy, dysarthria, axial rigidity, frontal lobe dysfunction, and dementia. The typical pathology includes neuronal loss, gliosis and microtubule-associated protein tau (MAPT)-positive inclusions in neurons and glial cells, primarily in basal ganglia, brainstem and cerebellum. The pathogenesis of PSP is not yet completely understood; however, there are several hypotheses. This article reviews the present knowledge about PSP, and the concepts underlying mitochondrial dysfunction, lipoperoxidation, and gene mutations. The clinical features of PSP are also discussed; these include vertical gaze palsy, pseudobulbar palsy, aphasia, dysarthria, axial rigidity, and neuropsychiatric symptoms, such as amnesia, irritability, loss of interest, and dementia. In terms of diagnosis, there is considerable interest in neuroimaging for detecting PSP; therefore, neuroimaging techniques such as magnetic resonance imaging (MRI) and [18F]- fluorodeoxyglucose positron-emission tomography (FDG-PET) are reviewed. A definitive diagnosis of PSP depends on pathology, and the introduction of new clinical subtypes challenges presents the widely adopted diagnosis criteria. PSP treatments such as serotonin antagonists, α2 receptor antagonists, and coenzyme Q10 are also discussed. There is no curative therapy for PSP; all of the available treatments are palliative.

Whole exome sequencing of suspected mitochondrial patients in clinical practice.

Mitochondrial disorders are characterized by a broad clinical spectrum. Identical clinical signs and symptoms can be caused by mutations in different mitochondrial or nuclear genes. Vice versa, the same mutation can lead to different phenotypes. Genetic syndromes and neuromuscular disorders mimicking mitochondrial disorders further complicate the diagnostic process. Whole exome sequencing (WES) is the state of the art next generation sequencing technique to identify genetic defects in mitochondrial disorders. Until recently it has mainly been used as a research tool. In this study, the use of WES in routine diagnostics is described. The WES data of 109 patients, referred under the suspicion of a mitochondrial disorder, were examined in two steps. First, the data were filtered using a virtual gene panel of genes known to be associated with mitochondrial disease. If negative, the entire exome was examined. A molecular diagnosis was achieved in 39 % of the heterogeneous cohort, and in 57 % of the subgroup of 42 patients with the highest suspicion for a mitochondrial disease. In addition to mutations in genes known to be associated with mitochondrial disorders (e.g. TUFM, MTFMT, FBXL4), in the subgroup of patients with the lowest suspicion for a mitochondrial disorder we found mutations in several genes associated with neuromuscular disorders (e.g. SEPN1, ACTA1) and genetic syndrome (e.g. SETBP1, ARID1B). Our results show that WES technology has been successfully implemented as a state-of-the-art, molecular diagnostic test for mitochondrial disorders as well as for the mimicking disorders in daily clinical practice. It also illustrates that clinical and biochemical phenotyping is essential for successful application of WES to diagnose individual patients.

A novel mutation MT-COIII m.9267G>C and MT-COI m.5913G>A mutation in mitochondrial genes in a Tunisian family with maternally inherited diabetes and deafness (MIDD) associated with sever nephropathy

Mitochondrial diabetes (MD) is a heterogeneous disorder characterized by a chronic hyperglycemia, maternal transmission and its association with a bilateral hearing impairment. Several studies reported mutations in mitochondrial genes as potentially pathogenic for diabetes, since mitochondrial oxidative phosphorylation plays an important role in glucose-stimulated insulin secretion from beta cells. In the present report, we studied a Tunisian family with mitochondrial diabetes (MD) and deafness associated with nephropathy. The mutational analysis screening revealed the presence of a novel heteroplasmic mutation m.9276G>C in the mitochondrial COIII gene, detected in mtDNA extracted from leukocytes of a mother and her two daughters indicating that this mutation is maternally transmitted and suggest its implication in the observed phenotype.Bioinformatic tools showed that m.9267G>C mutation (p.A21P) is « deleterious » and it can modify the function and the stability of the MT-COIII protein by affecting the assembly of mitochondrial COX subunits and the translocation of protons then reducing the activity of the respective OXPHOS complexes of ATP synthesis.The nonsynonymous mutation (p.A21P) has not been reported before, it is the first mutation described in the COXIII gene which is related to insulin dependent mitochondrial diabetes and deafness and could be specific to the Tunisian population. The m.9267G>C mutation was present with a nonsynonymous inherited mitochondrial homoplasmic variation MT-COI m.5913 G>A (D4N) responsible of high blood pressure, a clinical feature detected in all explored patients.

Identification of a novel mutation of PJVK in the Chinese non-syndromic hearing loss population with low prevalence of the PJVK mutations

Conclusion: To our knowledge, this is the first report of PJVK gene mutation in a Chinese non-syndromic sensorineural hearing loss (NSHL) family. Our data indicate that the PJVK gene contributes to hearing impairment in the Chinese population, but it is not a major cause. Objective: To investigate the contribution of PJVK mutations to NSHL in the Chinese population. Methods: We screened for the PJVK gene in a sample of 65 autosomal recessive NSHL families without GJB2, SLC26A4, or mitochondrial 12S rRNA gene mutations. Seven pairs of PCR primers were designed to amplify all of the exons and their flanking regions of the PJVK gene. The PCR products were sequenced and analyzed for identification of mutations. Results: In all, we identified one novel frameshift mutation, c.930_931del AC (p.C312W fsX19), co-segregating with the phenotype in one consanguineous family with a prevalence of 1.5% (1/65). The p.C312W fsX19 mutation was just positioned in the zinc-fingers domain, which was important to the function of pejvakin, and resulted in a stop codon after 19 additional amino acids. It was not identified in the controls and was considered as the causative mutation of family 804566 with autosomal recessive, non-syndromic, prelingual sensorineural hearing impairment.

ROS and energy metabolism in cancer cells: alliance for fast growth.

In normal cells, the cellular reactive oxygen species (ROS) level is proportional to the activity of mitochondrial electron transport and tightly controlled by endogenous antioxidant system. However, energy metabolism and ROS homeostasis in cancer cells are much different from those in normal cells. For example, a majority of cellular glucose is metabolized through aerobic glycolysis ("Warburg effect") and the pentose phosphate pathway. Cancer cells harbor functional mitochondria, but many mutations in nuclear DNA-encoded mitochondrial genes and mitochondrial genome result in the mitochondrial metabolic reprogramming. The other characteristic of cancer cells is to maintain much higher ROS level than normal cells. Ironically, cancer cells overexpress the ROS-producing NADPH oxidase and the ROS-eliminating antioxidant enzymes, both of which enzyme systems share NADPH as a reducing power source. In this article, we review the complex connection between ROS and energy metabolisms in cancer cells.

Allotopic expression of ATP6 in the mouse as a transgenic model of mitochondrial disease.

Progress in animal modeling of polymorphisms and mutations in mitochondrial DNA (mtDNA) is not as developed as nuclear transgenesis due to a host of cellular and physiological distinctions. mtDNA mutation modeling is of critical importance as mutations in the mitochondrial genome give rise to a variety of pathological conditions and play a contributing role in many others. Nuclear localization and transcription of mtDNA genes followed by cytoplasmic translation and transport into mitochondria (allotopic expression, AE) provide an opportunity to create in vivo modeling of a targeted mutation in mitochondrial genes and has been suggested as a strategy for gene replacement therapy in patients harboring mitochondrial DNA mutations. Here, we use our AE approach to transgenic mouse modeling of the pathogenic human T8993G mutation in mtATP6 as a case study for designing AE animal models.

Twenty Two New Mutations in Mitochondrial tRNA Genes in Patients with Alzheimer's Tabriz, Iran

Alzheimer's disease is the main form of memory, and memory loss in the elderly is the interplay of genes and environment play a role in its formation. The role of mitochondrial mutations in various neurological diseases, has effectively proven that some of these mutations of Alzheimer's disease in a non-Mendelian maternal mode of inheritance that are inherited. All mitochondrial tRNA genes in 24 patients and 50 healthy controls using nucleotide sequences, was tested. Mitochondrial tRNA genes were found in fifteen change. The polymorphisms were eleven of them. Four changes T1633A, C1631A (in tRNA parents), T14723T, Q14704C, were classified as pathogenic mutations, such as heteroplasmy observed in patients, mutations of nucleotide sequences in different organisms has been identified. Polymorphism A12308G, eight patients were found in tRNA leucine. This change in various neurological diseases, as well as control samples has been reported. We believe that these changes may influence the pathogenesis of Alzheimer's disease or the disease process act as a secondary injury. The percentage of heteroplasmy may be involved in the development of symptoms or onset of the disease.

Mutation of mtDNA ND1 Gene in 20 Type 2 Diabetes Mellitus Patients of Gorontalonese and Javanese Ethnicity

Mitochondrial gene mutation plays a role in the development of type two diabetes mellitus (T2DM). A point mutation in the mitochondrial gene Nicotinamide adenine dinucleotide dehydrogenase 1 (mtDNA ND1) gene mainly reported as the most common mutation related to T2DM. However, several studies have identified another SNP (single-nucleotide polymorphisms) in the RNA region of mtDNA from patients from specific ethnic populations in Indonesia. Building on those findings, this study aimed to use PCR and DNA sequencing technology to identify nucleotides in RNA and ND1 fragment from 20 Gorontalonese and 20 Javanese T2DM patients, that may trigger T2DM expression. The results showed successful amplification of RNA along 294 bp for all samples. From these samples, we found two types of point mutation in Javanese patients in the G3316A and T3200C points of the rRNA and ND1 gene. In samples taken from Gorontalonese patients, no mutation were found in the RNA or ND1 region. We conclude that T2DM was triggered differently in our two populations. While genetic mutation is implicated for the 20 Javanese patients, T2DM pathogenesis in the Gorontalonese patients must be traced to other genetic, environmental, or behavioral factors.

Novel mutations in the displacement loop of mitochondrial DNA are associated with acute lymphoblastic leukemia: a genetic sequencing study.

Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children and represents approximately 25% of cancer diagnoses among those younger than 15 years of age. This study investigated alterations in the displacement loop (d-loop) region of mitochondrial DNA (mtDNA) as a risk factor and diagnostic biomarker for early detection and diagnosis of acute lymphoblastic leukemia. Using mtDNA from 23 subjects diagnosed with acute lymphoblastic leukemia, the first 450 bp of the d-loop region were amplified and successfully sequenced. This revealed 132 mutations at 25 positions in this region, with a mean of 6 alterations per subject. The d-loop alterations in mtDNA in subjects were all identified as single nucleotide polymorphisms in a homoplasmic distribution pattern. Mutant alleles were observed in all subjects with individual frequency rates of up to 95%. Thirteen mutant alleles in the d-loop region of mtDNA occurred with a high frequency. Novel alleles and locations were also identified in the d-loop of mtDNA as follows: 89 G insertions (40%), 95 G insertions (13%), 182 C/T substitutions (5%), 308 C insertions (19%), and 311 C insertions (80%). The findings of this study need to be replicated to be confirmed. Further investigation of the relationship between mutations in mitochondrial d-loop genes and incidence of acute lymphoblastic leukemia is recommended.

Mutations in mitochondrial DNA and approaches for their correction.

Apart from the nucleus, the mitochondrion is the only organelle of an animal cell that contains its own genome. Mitochondrial DNA is much less in size than the nuclear one and codes for only several dozens of biological macromolecules. Nevertheless, mutations in mitochondrial genes often result in the occurrence of serious hereditary neuromuscular diseases. New mitochondrial DNA mutations and their relations to clinical symptoms are continuously reported in the scientific literature. In this review, we summarize existing data about such mutations, and also about contemporary gene therapy approaches that have been developed for their suppression.

Identification of the rare compound heterozygous variants in the NEB gene in a Korean family with intellectual disability, epilepsy and early-childhood-onset generalized muscle weakness.

We examined a Korean family with complex phenotypes characterized by intellectual disability, epilepsy and early-childhood-onset generalized muscle weakness. Since we did not find any abnormality using several conventional genetic tests for detection of chromosomal aberrations, gene copy number variations and mitochondrial gene mutations, we aimed to identify disease-causing genetic alteration(s) in this family. We conducted whole-exome sequencing (WES) in this family. After filtering the WES data, we compared five exome sequences of two affected siblings, one unaffected sibling and the unaffected parents, and we determined the allele frequency of the identified variants in an Asian population. Finally, we selected one candidate variant pair which is unique in the patients and corresponds to an autosomal recessive genetic model. The two affected siblings had the same compound heterozygous variation in the NEB gene encoding nebulin, which was composed of two different missense variants: c.2603T>C (p.L868P) in exon 27 and c.21340C>T (p.R7114W) in exon 143. We confirmed these variations by Sanger sequencing. On the basis of the fundamental role of nebulin in the brain and skeletal muscles, we concluded that this compound heterozygous NEB variation may be a sound candidate for the disease-causing mutation in this family. Since the patients are characterized by generalized muscle weakness together with neurodevelopmental phenotypes, it is suggested that NEB mutations could manifest more diverse phenotypes than those previously described.

GW25-e2275 Mitochondrial tRNA-Thr Gene Mutation in Maternally Inherited Hypertension and the Regulatory Mechanism in Adiponectin Pathway

The offspring hypertension and mother hypertension has a significant correlation, and also, mtDNA mutations are related with elevated blood pressure, but the underlying mechanism is unclear. Based on a study with small sample size and two pedigrees maternal family mumbers, we tried to reveal the