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Sullivan RT, Raj JU, Austin ED. Recent Advances in Pediatric Pulmonary Hypertension: Implications for Diagnosis and Treatment. Clin Ther 2023; 45:901-912. [PMID: 37517916 DOI: 10.1016/j.clinthera.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/03/2023] [Accepted: 07/06/2023] [Indexed: 08/01/2023]
Abstract
PURPOSE Pediatric pulmonary hypertension (PH) is a condition characterized by elevated pulmonary arterial pressure, which has the potential to be life-limiting. The etiology of pediatric PH varies. When compared with adult cohorts, the etiology is often multifactorial, with contributions from prenatal, genetic, and developmental factors. This review aims to provide an up-to-date overview of the causes and classification of pediatric PH, describe current therapeutics in pediatric PH, and discuss upcoming and necessary research in pediatric PH. METHODS PubMed was searched for articles relating to pediatric pulmonary hypertension, with a particular focus on articles published within the past 10 years. Literature was reviewed for pertinent areas related to this topic. FINDINGS The evaluation and approach to pediatric PH are unique when compared with that of adults, in large part because of the different, often multifactorial, causes of the disease in children. Collaborative registry studies have found that the most common disease causes include developmental lung disease and subsets of pulmonary arterial hypertension, which includes genetic variants and PH associated with congenital heart disease. Treatment with PH-targeted therapies in pediatrics is often guided by extrapolation of adult data, small clinical studies in pediatrics, and/or expert consensus opinion. We review diagnostic considerations and treatment in some of the more common pediatric subpopulations of patients with PH, including developmental lung diseases, congenital heart disease, and trisomy 21. IMPLICATIONS The care of pediatric patients with PH requires consideration of unique pediatric-specific factors. With significant variability in disease etiology, ongoing efforts are needed to optimize treatment strategies based on disease phenotype and guide evidence-based practices.
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Affiliation(s)
- Rachel T Sullivan
- Department of Pediatrics, Division of Cardiology, Vanderbilt University Medical Center, Monroe Carrell Jr Children's Hospital, Nashville, Tennessee.
| | - J Usha Raj
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois
| | - Eric D Austin
- Department of Pediatrics, Division of Pulmonary Medicine, Vanderbilt University Medical Center, Monroe Carrell Jr Children's Hospital, Nashville, Tennessee
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Osteraas ND, Dafer RM. Advances in Management of the Stroke Etiology One-Percenters. Curr Neurol Neurosci Rep 2023; 23:301-325. [PMID: 37247169 PMCID: PMC10225785 DOI: 10.1007/s11910-023-01269-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2023] [Indexed: 05/30/2023]
Abstract
PURPOSE OF REVIEW Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as optimal management will in many cases differs significantly from "standard" care. RECENT FINDINGS Randomized controlled trials (RCT) on the best medical therapy in the treatment of cervical artery dissection (CeAD) have demonstrated low rates of ischemia with both antiplatelet and vitamin K antagonism. RCT evidence supports the use of anticoagulation with vitamin K antagonism in "high-risk" patients with antiphospholipid antibody syndrome (APLAS), and there is new evidence supporting the utilization of direct oral anticoagulation in malignancy-associated thrombosis. Migraine with aura has been more conclusively linked not only with increased risk of ischemic and hemorrhagic stroke, but also with cardiovascular mortality. Recent literature has surprisingly not provided support the utilization of L-arginine in the treatment of patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); however, there is evidence at this time that support use of enzyme replacement in patients with Fabry disease. Additional triggers for reversible cerebral vasoconstriction syndrome (RCVS) have been identified, such as capsaicin. Imaging of cerebral blood vessel walls utilizing contrast-enhanced MRA is an emerging modality that may ultimately prove to be very useful in the evaluation of patients with uncommon causes of stroke. A plethora of associations between cerebrovascular disease and COVID-19 have been described. Where pertinent, authors provide additional tips and guidance. Less commonly encountered conditions with updates in diagnosis, and management along with clinical tips are reviewed.
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Affiliation(s)
| | - Rima M Dafer
- Rush University Medical Center, Chicago, IL, USA.
- Department of Neurological Sciences, Rush University Medical Center, 1725 W. Harrison St., Suite 1118, Chicago, IL, 60612, USA.
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Sakata A, Kashio A, Koyama H, Uranaka T, Iwasaki S, Fujimoto C, Kinoshita M, Yamasoba T. Long-Term Progression and Rapid Decline in Hearing Loss in Patients with a Point Mutation at Nucleotide 3243 of the Mitochondrial DNA. Life (Basel) 2022; 12:life12040543. [PMID: 35455034 PMCID: PMC9033132 DOI: 10.3390/life12040543] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/03/2022] [Accepted: 04/04/2022] [Indexed: 11/16/2022] Open
Abstract
Patients with m.3243A>G mutation of mitochondrial DNA develop bilaterally symmetric sensorineural hearing loss. However, it is unclear how fast their hearing loss progresses over time, and whether they experience rapid progression of hearing loss. In the present study, we conducted a long-term hearing evaluation in patients with MELAS or MIDD who harbored the m.3243A>G mutation of mitochondrial DNA. A retrospective chart review was performed on 15 patients with this mutation who underwent pure-tone audiometry at least once a year for more than two years. The mean follow-up period was 12.8 years. The mean progression rate of hearing loss was 5.5 dB per year. Hearing loss progressed rapidly to be profoundly deaf in seven patients during the observation period. Heteroplasmy and age-corrected heteroplasmy levels correlated with the age of onset of hearing loss. These results indicate that patients with m.3243A>G mutation have a gradual progression of hearing loss in the early stages and rapid decline in hearing to be profoundly deaf in approximately half of the patients. Although it is possible to predict the age of onset of hearing loss from heteroplasmy and age-corrected heteroplasmy levels, it is difficult to predict whether and when the rapid hearing loss will occur.
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Affiliation(s)
- Aki Sakata
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Akinori Kashio
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Hajime Koyama
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Tsukasa Uranaka
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Shinichi Iwasaki
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, Nagoya City University, Aichi 467-8601, Japan
| | - Chisato Fujimoto
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Makoto Kinoshita
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
| | - Tatsuya Yamasoba
- Department of Otolaryngology and Head and Neck Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8654, Japan; (A.S.); (A.K.); (H.K.); (T.U.); (S.I.); (C.F.); (M.K.)
- Correspondence: ; Tel.: +81-3-3815-5411
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The Role of Mitochondrial DNA Mutations in Cardiovascular Diseases. Int J Mol Sci 2022; 23:ijms23020952. [PMID: 35055137 PMCID: PMC8778138 DOI: 10.3390/ijms23020952] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/08/2022] [Accepted: 01/14/2022] [Indexed: 02/01/2023] Open
Abstract
Cardiovascular diseases (CVD) are one of the leading causes of morbidity and mortality worldwide. mtDNA (mitochondrial DNA) mutations are known to participate in the development and progression of some CVD. Moreover, specific types of mitochondria-mediated CVD have been discovered, such as MIEH (maternally inherited essential hypertension) and maternally inherited CHD (coronary heart disease). Maternally inherited mitochondrial CVD is caused by certain mutations in the mtDNA, which encode structural mitochondrial proteins and mitochondrial tRNA. In this review, we focus on recently identified mtDNA mutations associated with CVD (coronary artery disease and hypertension). Additionally, new data suggest the role of mtDNA mutations in Brugada syndrome and ischemic stroke, which before were considered only as a result of mutations in nuclear genes. Moreover, we discuss the molecular mechanisms of mtDNA involvement in the development of the disease.
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de Laat P, Rodenburg RR, Roeleveld N, Koene S, Smeitink JA, Janssen MC. Six-year prospective follow-up study in 151 carriers of the mitochondrial DNA 3243 A>G variant. J Med Genet 2020; 58:48-55. [PMID: 32439810 DOI: 10.1136/jmedgenet-2019-106800] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/12/2020] [Accepted: 03/13/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND The mitochondrial DNA (mDNA) 3243A>G variant is the most common pathogenic variant of the mDNA. To interpret results of clinical trials in mitochondrial disease, it is important to have a clear understanding of the natural course of disease. To obtain more insight into the disease burden and the progression of disease in carriers of the mDNA 3243 A>G variant, we followed a cohort of 151 carriers from 61 families prospectively for up to 6 years. METHODS The disease severity was scored using the Newcastle Mitochondrial Disease Adult Scale (NMDAS), including SF-36 quality of life (QoL) scores. Heteroplasmy levels were measured in urinary epithelial cells (UEC), leucocytes and saliva. The progression of the disease was studied using linear mixed model analysis. RESULTS One hundred twenty-four carriers (out of 151) were symptomatic. Four clinical groups were identified: 1) classical mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome (n=7), 2) maternally inherited diabetes deafness syndrome (n=60), 3) 'other' (n=57) and 4) dormant carriers (n=27). A yearly increase of NMDAS score of 0.47 point was measured in the total group. Heteroplasmy levels in both leucocytes and UEC were only weakly correlated with disease severity. Physical QoL declined with age. The most important determinants of QoL decline were hearing loss, speech problems, exercise intolerance, gait instability, psychiatric problems and gastrointestinal involvement. CONCLUSION The mDNA 3243 A>G variant causes a slowly progressive disease, with a yearly increase of NMDAS score of ~0.5 point overall with the clinical phenotype being the only determinant of disease progression.
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Affiliation(s)
- Paul de Laat
- Radboudumc Amalia Children's Hospital, Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Richard R Rodenburg
- Radboudumc Amalia Children's Hospital, Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Nel Roeleveld
- Department for Health Evidence, Radboudumc, Nijmegen, Gelderland, The Netherlands
| | - Saskia Koene
- Radboudumc Amalia Children's Hospital, Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Jan A Smeitink
- Radboudumc Amalia Children's Hospital, Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Mirian Ch Janssen
- Department of Internal Medicine, Radboudumc, Nijmegen, The Netherlands
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Zhang Z, Liu M, He J, Zhang X, Chen Y, Li H. Maternally inherited coronary heart disease is associated with a novel mitochondrial tRNA mutation. BMC Cardiovasc Disord 2019; 19:293. [PMID: 31842766 PMCID: PMC6912950 DOI: 10.1186/s12872-019-01284-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/27/2019] [Indexed: 01/26/2023] Open
Abstract
Background Coronary heart disease (CHD) is the most common cause of mortality globally, yet mitochondrial genetic mutations associated with CHD development remain incompletely understood. Methods The subjects from three Chinese families with LHON underwent clinical, genetic, molecular, and biochemical evaluations. Biochemical characterizations included measuring the effects of the15910C > T mutation on tRNAThr levels, enzymatic activity of electron transport chain complexes, membrane permeability, and the mitochondria-mediated generation of both reactive oxygen species (ROS) and adenosine triphosphate (ATP). Results We characterize mitochondrial genetic mutations in a three-generation Chinese family exhibiting signs of maternally inherited CHD. Of the 24 different family members in this pedigree we assessed, CHD was detected in 6, with variable severity and age of first appearance. When we sequenced the mitochondrial genomes of these individuals, we found a tRNAThr 15910C > T mutation of the Eastern Asian haplogroup M7b’c. This mutation is predicted to destabilize the strongly conserved (24C-10G) base-pairing, thereby disrupting tRNAThr functionality. When we performed Northern blotting, we detected we observed a 37.5% reduction in tRNAThr levels at baseline in cybrid cell lines bearing the 15910C > T mutation. When we conducted western blot analysis, we detected a ~ 24.96% decrease in mitochondrial translation rates in these same cells. Conclusions In the present report, Together these findings suggest a possible link between this 15910C > T tRNAThr mutation and CHD, potentially offering new avenues for future disease intervention.
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Affiliation(s)
- Zhenxiao Zhang
- Department of Emergency, Affiliated hospital of Qingdao university, Jiangsu Road No. 16, Qingdao, 266000, Shandong, China
| | - Mingyang Liu
- Department of Emergency, Affiliated hospital of Qingdao university, Jiangsu Road No. 16, Qingdao, 266000, Shandong, China
| | - Jianshuai He
- Department of Anesthesiology, Affiliated hospital of Qingdao university, Qingdao, 266000, Shandong, China
| | - Xiaotian Zhang
- Department of Anesthesiology, Affiliated hospital of Qingdao university, Qingdao, 266000, Shandong, China
| | - Yuehua Chen
- Department of ICU, Affiliated hospital of Qingdao university, Qingdao, 266000, Shandong, China
| | - Hui Li
- Department of Emergency, Affiliated hospital of Qingdao university, Jiangsu Road No. 16, Qingdao, 266000, Shandong, China.
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de Laat P, van Engelen N, Wetzels JF, Smeitink JAM, Janssen MCH. Five non-mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes phenotype adult patients with m.3243A>G mutation after kidney transplantation: follow-up and review of the literature. Clin Kidney J 2019; 12:840-846. [PMID: 31807297 PMCID: PMC6885678 DOI: 10.1093/ckj/sfz020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Indexed: 01/07/2023] Open
Abstract
Background Renal involvement in patients with the m.3243A>G mutation may result in end-stage renal disease (ESRD) requiring renal replacement therapy. Although kidney transplantations have been performed in a small number of patients, short- and long-term follow-up data are lacking. Methods We describe five patients with the m.3243A<G mutation who received a kidney transplant, including follow-up data up to 13 years. We also summarize all cases (n = 13) of kidney transplantation in m.3243A>G carriers described in the literature. Results Proteinuria with or without renal failure was the first clinical presentation of renal involvement in 13 of 18 (72%) patients. Focal segmental glomerulosclerosis (FSGS) was found in 9 of 13 (69%) biopsies. Sixteen of 18 (84%) patients developed hearing loss. All patients were diagnosed with diabetes mellitus, of whom eight (44%) developed the disease after transplantation. All patients with reported follow-up data (13/18) had stable kidney function from 6 months to 13 years of follow-up after transplantation. Conclusions Renal involvement in carriers of the m.3243A>G mutation most commonly leads to proteinuria and FSGS and may lead to ESRD. Proper recognition of the mitochondrial origin of the renal disease in these patients is important for adequate treatment selection and suitable supportive care. This case series and review of the available literature on long-term follow-up after kidney transplantation shows it is feasible for non-mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes phenotype carriers of the m.3243A>G mutation to be considered for kidney transplantation in case of ESRD. These patients should not be excluded from transplant solely for their mitochondrial diagnosis.
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Affiliation(s)
- Paul de Laat
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Nienke van Engelen
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Jack F Wetzels
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jan A M Smeitink
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Mirian C H Janssen
- Department of Pediatrics, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center Amalia Children's Hospital, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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8
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de Laat P, Rodenburg RJ, Smeitink JAM, Janssen MCH. Intra-patient variability of heteroplasmy levels in urinary epithelial cells in carriers of the m.3243A>G mutation. Mol Genet Genomic Med 2018; 7:e00523. [PMID: 30516030 PMCID: PMC6393655 DOI: 10.1002/mgg3.523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/13/2018] [Accepted: 10/17/2018] [Indexed: 11/18/2022] Open
Abstract
Background The mitochondrial DNA m.3243A>G mutation is one the most prevalent mutation causing mitochondrial disease in adult patients. Several cohort studies have used heteroplasmy levels in urinary epithelial cells (UEC) to correlate the genotype of the patients to the clinical severity. However, the interpretation of these data is hampered by a lack of knowledge on the intra‐patient variability of the heteroplasmy levels. The goal of this study was to determine the day‐to‐day variation of the heteroplasmy levels in UEC. Methods Fifteen carriers of the m.3243A>G mutation collected five urine samples in a 14‐day window. Heteroplasmy levels of the m.3243A>G mutation were determined in these samples. Data from the national cohort study, including Newcastle Mitochondrial Disease Adult Scale scores and clinical diagnosis, were used. Results In the samples of six patients, heteroplasmy levels were within a 5% margin. In the samples collected from five patients, the margin was >20%. Conclusion Heteroplasmy levels of UEC in carriers of the m.3243A>G mutation have a significant day‐to‐day variation. The interpretation of a correlation between heteroplasmy levels in urine and disease severity is therefore not reliable. Therefore, heteroplasmy levels in UEC should not be used as a prognostic biomarker in these patients.
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Affiliation(s)
- Paul de Laat
- Department of Pediatrics, Radboudumc Amalia Childrens Hospital, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Richard J Rodenburg
- Department of Pediatrics, Radboudumc Amalia Childrens Hospital, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Jan A M Smeitink
- Department of Pediatrics, Radboudumc Amalia Childrens Hospital, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
| | - Mirian C H Janssen
- Department of Pediatrics, Radboudumc Amalia Childrens Hospital, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands.,Department of Internal Medicine, Radboudumc, Radboud Center for Mitochondrial Medicine, Nijmegen, The Netherlands
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Zhang Z, Zhao D, Zhang X, Xiong H, Bao X, Yuan Y, Wang Z. Survival analysis of a cohort of Chinese patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) based on clinical features. J Neurol Sci 2018; 385:151-155. [DOI: 10.1016/j.jns.2017.12.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 11/22/2017] [Accepted: 12/27/2017] [Indexed: 12/15/2022]
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Venter M, van der Westhuizen FH, Elson JL. The aetiology of cardiovascular disease: a role for mitochondrial DNA? Cardiovasc J Afr 2017; 29:122-132. [PMID: 28906532 PMCID: PMC6009096 DOI: 10.5830/cvja-2017-037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 07/17/2017] [Indexed: 01/03/2023] Open
Abstract
Cardiovascular disease (CVD) is a world-wide cause of mortality in humans and its incidence is on the rise in Africa. In this review, we discuss the putative role of mitochondrial dysfunction in the aetiology of CVD and consequently identify mitochondrial DNA (mtDNA) variation as a viable genetic risk factor to be considered. We then describe the contribution and pitfalls of several current approaches used when investigating mtDNA in relation to complex disease. We also propose an alternative approach, the adjusted mutational load hypothesis, which would have greater statistical power with cohorts of moderate size, and is less likely to be affected by population stratification. We therefore address some of the shortcomings of the current haplogroup association approach. Finally, we discuss the unique challenges faced by studies done on African populations, and recommend the most viable methods to use when investigating mtDNA variation in CVD and other common complex disease.
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Affiliation(s)
- Marianne Venter
- Human Metabolomics, North-West University, Potchefstroom, South Africa.
| | | | - Joanna L Elson
- Human Metabolomics, North-West University, Potchefstroom, South Africa; Institute of Genetic Medicine, Newcastle University, United Kingdom
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Abstract
PURPOSE OF REVIEW Cardiovascular disease (CVD) is responsible for more morbidity and mortality worldwide than any other ailment. Strategies for reducing CVD prevalence must involve identification of individuals at high risk for these diseases, and the prevention of its initial development. Such preventive efforts are currently limited by an incomplete understanding of the genetic determinants of CVD risk. In this review, evidence for the involvement of inherited mitochondrial mutations in development of CVD is examined. RECENT FINDINGS Several forms of CVD have been documented in the presence of pathogenic mitochondrial DNA (mtDNA) mutations, both in isolation and as part of larger syndromes. Other 'natural' mtDNA polymorphisms not overtly tied to any pathology have also been associated with alterations in mitochondrial function and individual risk for CVD, but until very recently these studies have been merely correlative. Fortunately, novel animal models are now allowing investigators to define a causal relationship between inherited 'natural' mtDNA polymorphisms, and cardiovascular function and pathology. SUMMARY Cardiovascular involvement is highly prevalent among patients with pathogenic mtDNA mutations. The relationship between CVD susceptibility and 'natural' mtDNA polymorphisms requires further investigation, but will be aided in the near future by several novel experimental models.
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Affiliation(s)
- Alexander W. Bray
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham
| | - Scott W. Ballinger
- Division of Molecular and Cellular Pathology, Department of Pathology, University of Alabama at Birmingham
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Finsterer J, Kothari S. Cardiac manifestations of primary mitochondrial disorders. Int J Cardiol 2014; 177:754-63. [PMID: 25465824 DOI: 10.1016/j.ijcard.2014.11.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/23/2014] [Accepted: 11/03/2014] [Indexed: 12/16/2022]
Abstract
OBJECTIVES One of the most frequently affected organs in mitochondrial disorders (MIDs), defined as hereditary diseases due to affection of the mitochondrial energy metabolism, is the heart. Cardiac involvement (CI) in MIDs has therapeutic and prognostic implications. This review aims at summarizing and discussing the various cardiac manifestations in MIDs. METHODS Data for this review were identified by searches of MEDLINE, Current Contents, and PubMed using appropriate search terms. RESULTS CI in MIDs may be classified according to various different criteria. In the present review cardiac abnormalities in MIDs are discussed according to their frequency with which they occur. CI in MIDs includes cardiomyopathy, arrhythmias, heart failure, pulmonary hypertension, dilation of the aortic root, pericardial effusion, coronary heart disease, autonomous nervous system dysfunction, congenital heart defects, or sudden cardiac death. The most frequent among the cardiomyopathies is hypertrophic cardiomyopathy, followed by dilated cardiomyopathy, and noncompaction. CONCLUSIONS CI in MID is more variable and prevalent than previously thought. All tissues of the heart may be variably affected. The most frequently affected tissue is the myocardium. MIDs should be included in the differential diagnoses of cardiac disease.
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Horga A, Pitceathly RDS, Blake JC, Woodward CE, Zapater P, Fratter C, Mudanohwo EE, Plant GT, Houlden H, Sweeney MG, Hanna MG, Reilly MM. Peripheral neuropathy predicts nuclear gene defect in patients with mitochondrial ophthalmoplegia. ACTA ACUST UNITED AC 2014; 137:3200-12. [PMID: 25281868 PMCID: PMC4240292 DOI: 10.1093/brain/awu279] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mitochondrial ophthalmoplegia is a genetically heterogeneous disorder. Horga et al. investigate whether peripheral neuropathy can predict the underlying genetic defect in patients with progressive external ophthalmoplegia. Results indicate that neuropathy is highly predictive of a nuclear DNA defect and that it is rarely associated with single mitochondrial DNA deletions. Progressive external ophthalmoplegia is a common clinical feature in mitochondrial disease caused by nuclear DNA defects and single, large-scale mitochondrial DNA deletions and is less frequently associated with point mutations of mitochondrial DNA. Peripheral neuropathy is also a frequent manifestation of mitochondrial disease, although its prevalence and characteristics varies considerably among the different syndromes and genetic aetiologies. Based on clinical observations, we systematically investigated whether the presence of peripheral neuropathy could predict the underlying genetic defect in patients with progressive external ophthalmoplegia. We analysed detailed demographic, clinical and neurophysiological data from 116 patients with genetically-defined mitochondrial disease and progressive external ophthalmoplegia. Seventy-eight patients (67%) had a single mitochondrial DNA deletion, 12 (10%) had a point mutation of mitochondrial DNA and 26 (22%) had mutations in either POLG, C10orf2 or RRM2B, or had multiple mitochondrial DNA deletions in muscle without an identified nuclear gene defect. Seventy-seven patients had neurophysiological studies; of these, 16 patients (21%) had a large-fibre peripheral neuropathy. The prevalence of peripheral neuropathy was significantly lower in patients with a single mitochondrial DNA deletion (2%) as compared to those with a point mutation of mitochondrial DNA or with a nuclear DNA defect (44% and 52%, respectively; P < 0.001). Univariate analyses revealed significant differences in the distribution of other clinical features between genotypes, including age at disease onset, gender, family history, progressive external ophthalmoplegia at clinical presentation, hearing loss, pigmentary retinopathy and extrapyramidal features. However, binomial logistic regression analysis identified peripheral neuropathy as the only independent predictor associated with a nuclear DNA defect (P = 0.002; odds ratio 8.43, 95% confidence interval 2.24–31.76). Multinomial logistic regression analysis identified peripheral neuropathy, family history and hearing loss as significant predictors of the genotype, and the same three variables showed the highest performance in genotype classification in a decision tree analysis. Of these variables, peripheral neuropathy had the highest specificity (91%), negative predictive value (83%) and positive likelihood ratio (5.87) for the diagnosis of a nuclear DNA defect. These results indicate that peripheral neuropathy is a rare finding in patients with single mitochondrial DNA deletions but that it is highly predictive of an underlying nuclear DNA defect. This observation may facilitate the development of diagnostic algorithms. We suggest that nuclear gene testing may enable a more rapid diagnosis and avoid muscle biopsy in patients with progressive external ophthalmoplegia and peripheral neuropathy.
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Affiliation(s)
- Alejandro Horga
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Robert D S Pitceathly
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Julian C Blake
- 2 Department of Clinical Neurophysiology, Norfolk and Norwich University Hospital, Norwich, NR4 7UY, UK
| | - Catherine E Woodward
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Pedro Zapater
- 4 Clinical Pharmacology Section, Hospital General Universitario, Alicante, 03010, Spain
| | - Carl Fratter
- 5 Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Trust, Oxford, OX3 7LE, UK
| | - Ese E Mudanohwo
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Gordon T Plant
- 6 National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Henry Houlden
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Mary G Sweeney
- 3 Neurogenetics Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Michael G Hanna
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Mary M Reilly
- 1 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
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