OBJECTIVE: To explore the genetic basis for a Chinese pedigree with suspected mitochondrial functional defects through combined next-generation sequencing (NGS), copy number variation sequencing (CNV-seq), and mitochondrial DNA (mtDNA) sequencing. METHODS: Clinical data of the proband and his family members were collected. The patient and his parents were subjected to family-trio whole-exome sequencing (WES), CNV-seq and mtDNA variant detection. Candidate variant was verified by Sanger sequencing. RESULTS: Trio-WES revealed that the proband has carried compound heterozygous variants of the NDUFS1 gene, including a paternally derived c.64C>T (p.R22X) nonsense variant and a maternally derived c.845A>G (p.N282S) missense variant. Both variants may cause loss of protein function. No variant that may cause the phenotype was identified by CNV-seq and mtDNA variant analysis. CONCLUSION Children with suspected mitochondrial disorders may have no specific syndromes or laboratory findings. A comprehensive strategy including mtDNA testing may facilitate the diagnosis and early clinical interventions.
Child ; China ; DNA Copy Number Variations ; Electron Transport ; Humans ; Mutation ; NADH Dehydrogenase/genetics* ; Pedigree

OBJECTIVEThis study aimed to investigate the genetic background of mitochondrial genes in young patients with Coronary heart disease (CHD) to provide a foundation for the early prevention of young patients with CHD.

METHODS115 cases of young (⋜ 45 years) CHD Chinese Han patients (case group), 100 cases of older (> 45 years) Chinese Han CHD patients (experimental group) hospitalized and 100 cases of healthy people through physical examination (control group) at the General Hospital of PLA between January 2014 and December 2015 were selected. General information, clinical assessment, pedigree analysis, and mitochondrial full sequence scanning were performed. The pedigrees of one patient harbouring the C5263T mutation were recruited. Mitochondrial functional analysis including cellular reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were performed on pedigrees with the C5263T mutation (mutation group) and without the mutation (non-mutation group).

RESULTSThe differences in biochemical tests (P > 0.05) between the case group and experimental group were not significant. The C5263T single-nucleotide mutation of the mitochondrial ND2 gene was observed in 2 young CHD patients in the case group. The premature CHD of these 2 patients followed a pattern of maternal inheritance. The mutation group (I1, II2) had higher ROS levels (4750.82 ± 1045.55 vs. 3888.58 ± 487.60, P = 0.022) and lower MMP levels (P = 0.045) than the non-mutation group (II1, III1, III2).

CONCLUSIONWe speculated that the mitochondrial C5263T mutation might be associated with the occurrence CHD in Chinese Han young people.

Adult ; Aged ; Aged, 80 and over ; Base Sequence ; China ; epidemiology ; Coronary Disease ; epidemiology ; genetics ; Female ; Genes, Mitochondrial ; Humans ; Male ; Middle Aged ; Mitochondrial Proteins ; genetics ; metabolism ; Mutation ; NADH Dehydrogenase ; genetics ; metabolism

OBJECTIVETo investigate the role of MT-ND1 m.3635G>A mutation in the pathogenesis of Leber's hereditary optic neuropathy (LHON).

METHODSBiochemical characteristics including the activity of complex Ⅰ, ATP production and oxygen consumption rate among lymphoblastoid cell lines derived from 3 carriers, 3 affected matrilineal relatives of the families and 3 controls were compared.

RESULTSComparison of mitochondrial functions in lymphoblastoid cell lines of the carriers, patients and controls showed a 51.0% decrease in the activity of complex Ⅰ in patients compared with controls (P<0.05). The m.3635G>A mutation has resulted in decreased efficiency of ATP synthesis (P<0.05). Comparison of oxygen consumption rate showed that the basal OCR (P<0.05), ATP-linked OCR (P<0.05) and the maximum OCR (P<0.05) have all reduced to some extent compared with the controls.

CONCLUSIONThese results showed that m.3635G>A, as a LHON-associated mutation, can lead to mitochondrial dysfunction.

Adenosine Triphosphate ; genetics ; Asian Continental Ancestry Group ; genetics ; Female ; Humans ; Male ; Mitochondria ; genetics ; Mutation ; genetics ; NADH Dehydrogenase ; genetics ; Optic Atrophy, Hereditary, Leber ; genetics ; Pedigree

OBJECTIVETo report on the clinical, genetic and molecular characteristics of three ethnic Han Chinese families affected with Leber's hereditary optic neuropathy (LHON).

METHODSThe three families were all diagnosed with LHON. Ophthalmologic examinations were conducted on the probands . The ND1, ND4 and ND6 genes of the mitochondrial DNA (mtDNA) were amplified with PCR respectively for the screening of three primary mutations G3460A, G11778A and T14484C. The entire mtDNA of the probands were also amplified by PCR.

RESULTSAnalysis of mtDNA in the three pedigrees has failed to find the presence of the three LHON associated mutations but presence of a homoplastic ND1 T3866C mutation in all probands and their matrilineal relatives . The probands had different levels of visual impairment. The penetrance in the three families has been calculated as 12.5%, 11.1% and 33.3%, respectively. The T3866C mutation has resulted in replacement of isoleucine at position 187 with theronine. The isoleucine at position 187 is located at one of the transmembrane domains of ND1 polypeptide.

CONCLUSIONAbove results have suggested that the ND1 T3866C mutation might have been involved in the pathogenesis of LHON in the three Chinese families studied.

Adolescent ; Asian Continental Ancestry Group ; ethnology ; genetics ; Base Sequence ; Child ; Female ; Humans ; Male ; Mitochondria ; genetics ; Molecular Sequence Data ; NADH Dehydrogenase ; genetics ; Optic Atrophy, Hereditary, Leber ; ethnology ; genetics ; Pedigree ; Point Mutation

OBJECTIVETo study the effects of indium exposure on the relative content of mitochondrial ND1 gene in lymphocytes.

METHODSVenous blood was obtained from 14 healthy workers and anticoagulated with heparin. Blood lymphocytes were separated and divided into three tube cultures. For two tubes in the exposed group, indium chloride was added to final concentrations of 0.2 mmol/L and 0.8 mmol/L, respectively. For one tube in the control group, an equal volume of normal saline solution was added. After incubation for 72 h, the relative content of mitochondrial gene in each group was determined using quantitative real-time PCR.

RESULTSLymphocytes exposed to 0.8 mmol/L indium chloride had a significantly higher relative content of mitochondrial gene than those exposed to 0.2 mmol/L indium chloride and those in the control group (P < 0.05, P < 0.05).

CONCLUSIONLymphocytes exposed to a high concentration of indium and its compounds have an elevated relative content of mitochondrial ND1 gene, indicating increased oxidative DNA damage induced by exposure to a high concentration of indium and its compounds.

DNA Damage ; drug effects ; DNA, Mitochondrial ; genetics ; Humans ; Indium ; toxicity ; Lymphocytes ; drug effects ; NADH Dehydrogenase ; genetics ; Occupational Exposure

OBJECTIVETo investigate the relationship of the mutational status of the ND4 gene and the clinical features of acute myelogenous leukemia (AML) patients with ND4 mutations.

METHODSUsing PCR combined with directly sequencing, we identified somatic mutations of ND4 in 121 primary AML patients to couple with their clinical features.

RESULTSThere were 58 male patients and 63 female patients (median age 49 years, 10-86 years). Eight of 121 patients (6.6%) with de novo AML were found harboring missense mutation of ND4 gene, including 3 patients with A131V (3/8, 37.5%), 2 patients with A404T (2/8, 25%), 1 patient with F149L (1/8, 12.5%), 1 patient with G242D (1/8, 12.5%) and 1 patient with Y409H (1/8, 12.5%), respectively. Patients with ND4 mutations were associated with good karyotype (P=0.049), regardless of gender, age, white blood cell, hemoglobin, platelet, blast cells of bone marrow or immunophenotype (P>0.05). There were no statistical significance in mutations of FLT3-ITD, NPM1, CEBPA, c-KIT and DNMT3A between patients with ND4 mutation and wild-type (wt) ND4 (P>0.05). The median overall survival of patients with ND4 mutations and wt ND4 were all not reached. The median relapse-free survival were not reached and 29(2-53) months, respectively (P>0.05). There was no significance in the ratio of CR and RR patients between wt ND4 and ND4 mutated groups (P>0.05).

CONCLUSIONIt was concluded that novel ND4 mutations could be found in de novo AML patients, especially in patients with good karyotype. Thus, ND4 mutations might play an important role in AML prognosis. However, whether the mitochondria dysfunction contribute to leukemogenesis needs to be further investigated.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Female ; Humans ; Leukemia, Myeloid, Acute ; drug therapy ; genetics ; Male ; Middle Aged ; Mutation ; NADH Dehydrogenase ; genetics ; Prognosis ; Young Adult

OBJECTIVE: To test droplet digital PCR for species identification and absolute quantification of biological sample. METHODS: Specific primers and probes for human mtDNA encoding gene ND4 and 16S rRNA were designed, and the species-specificity was assessed on DNA samples derived from human and common animals. To determine the sensitivity and stability of droplet digital PCR for species identification and absolute quantification, gradient dilution series of recombinant plasmid and 16 human DNA samples were analyzed. RESULTS: Human recombinant plasmid FAM (ND4) could be used in detecting the samples of human. And the results of detecting were consistent with all levels of diluted concentrations. Droplet digital PCR was able to detect low and single copy of target DNA. CONCLUSION Droplet digital PCR, with high sensitivity and specificity, is fully amenable for species identification and absolute quantification of biological samples, also it can be applied on routine forensic examination.
Animals ; DNA ; DNA Primers/genetics* ; DNA, Mitochondrial/genetics* ; Humans ; NADH Dehydrogenase/genetics* ; Polymerase Chain Reaction/methods* ; RNA, Ribosomal, 16S/genetics* ; Sensitivity and Specificity ; Species Specificity

Opisthorchis viverrini and Clonorchis sinensis are parasites known to be carcinogenic and causative agents of cholangiocarcinoma in Asia. The standard method for diagnosis for those parasite infections is stool examination to detect parasite eggs. However, the method has low sensitivity, and eggs of O. viverrini and C. sinensis are difficult to distinguish from each other and from those of some other trematodes. Here, we report a multiplex real-time PCR coupled with high resolution melting (HRM) analysis for the differentiation of O. viverrini and C. sinensis eggs in fecal samples. Using 2 pairs of species-specific primers, DNA sequences from a portion of the mitochondrial NADH dehydrogenase subunit 2 (nad 2) gene, were amplified to generate 209 and 165 bp products for O. viverrini and C. sinensis, respectively. The distinct characteristics of HRM patterns were analyzed, and the melting temperatures peaked at 82.4+/-0.09degrees C and 85.9+/-0.08degrees C for O. viverrini and C. sinensis, respectively. This technique was able to detect as few as 1 egg of O. viverrini and 2 eggs of C. sinensis in a 150 mg fecal sample, which is equivalent to 7 and 14 eggs per gram of feces, respectively. The method is species-specific, rapid, simple, and does not require fluorescent probes or post-PCR processing for discrimination of eggs of the 2 species. It offers a new tool for differentiation and detection of Asian liver fluke infections in stool specimens.
Animals ; Asia ; Clonorchis sinensis/*classification/*genetics/isolation & purification ; Feces/parasitology ; Humans ; Multiplex Polymerase Chain Reaction/*methods ; NADH Dehydrogenase/genetics ; Opisthorchis/*classification/*genetics/isolation & purification ; Parasitology/*methods ; Real-Time Polymerase Chain Reaction/*methods ; Sensitivity and Specificity ; Transition Temperature ; Zygote

We describe a Korean family presenting with pediatric-onset, progressive, generalized dystonia with bilateral striatal necrosis and the homoplasmic G14459A mutation in the mitochondrial ND6 gene. The G14459A mutation has been reported in families presenting with Leber hereditary optic neuropathy (LHON) alone, LHON plus dystonia, or pediatric-onset dystonia. The proband had shown dysarthria, progressive generalized dystonia, and spasticity at 5 yr. Brain MRI demonstrated bilateral striatal necrosis. Additional investigation of family members revealed the presence of homoplasmic G14459A mutation in asymptomatic individuals. The clinical manifestation of the homoplasmic G14459A mtDNA mutation within the same family showed asymptomatic or pediatric-onset dystonia, without optic neuropathy. This study reemphasizes that the G14459A mutation is a candidate mutation for maternally inherited dystonia, regardless of optic neuropathy, and supports the hypothesis that nuclear genes may play a role in modifying the clinical expression of mitochondrial disease.
Adult ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; Brain/pathology ; Dystonia/complications/diagnosis/*genetics ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Mitochondrial Diseases/complications/diagnosis/*genetics ; NADH Dehydrogenase/*genetics ; Necrosis ; Optic Atrophy, Hereditary, Leber/genetics ; Pedigree ; *Point Mutation ; Republic of Korea

OBJECTIVETo identify differentially expressed genes in human embryo lung fibroblasts MRC-5 with adaptive response induced by low concentration of hydrogen peroxide (H(2)O(2)) using fluorescent differential display-RT-PCR (FDDRT-PCR).

METHODSThe dose-effect pattern of H2O2 toxicity was determined using MTT assay, and the dose of 0.088, 0.88, 8.8, 88 micro;mol/L was defined as the low concentration, and 1100 micromol/L as the high concentration. Adaptive response model was established in MRC-5 cells verified using LDH release and cell apoptosis analyses. Differentially expressed genes in the cells with exposure to different doses of H(2)O(2) were detected by FDDRT-PCR, and some of the differentially displayed genes were determined using real-time quantitative PCR.

RESULTSCells challenged with high-concentration H(2)O(2) for 1 h after H(2)O(2) pretreatment at low concentrations for 24 h resulted in lessened toxic effect in comparison with direct high-concentration H(2)O(2) exposure. The adaptive response of the cells was most obvious with H(2)O(2) pretreatment at 0.88 micromol/L. Altogether 60 differentially expressed genes were detected with FDDRT-PCR in different treatment groups, and 5 of them were identified and verified, including 1 unknown gene and 4 known genes (bcl-2, EIF3S5, NDUFS4 and RPS10).

CONCLUSIONAccording to the results of FDDRT-PCR, the genes bcl-2, EIF3S5, NDUFS4 and RPS10 can be involved in H(2)O(2)-induced adaptive response of the MRC-5 cells.

Adaptation, Physiological ; genetics ; Cell Line ; Cell Survival ; drug effects ; DNA, Complementary ; chemistry ; genetics ; Dose-Response Relationship, Drug ; Flow Cytometry ; Fluorescent Dyes ; chemistry ; Gene Expression Profiling ; Gene Expression Regulation ; drug effects ; Humans ; Hydrogen Peroxide ; pharmacology ; NADH Dehydrogenase ; genetics ; Oxidants ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; methods