1,203 results match your criteria: "Metabolic Disease and Stroke - MELAS"

Mitochondrial DNA (mtDNA) encodes genes essential for oxidative phosphorylation. The m.3243A>G mutation causes severe disease, including myopathy, lactic acidosis and stroke-like episodes (MELAS) and is the most common pathogenic mtDNA mutation in humans.

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  • * An elderly male patient with sudden onset dementia was initially misdiagnosed with a vascular issue, but further tests and imaging confirmed NIID, revealing significant cortical edema and prior MRI changes in the cerebellum.
  • * The case highlights the importance of considering NIID in patients with specific imaging features and symptoms similar to other conditions like MELAS syndrome or Creutzfeldt-Jakob disease, particularly when chronic headaches and symmetric lesions in the cerebellum are present.
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Variants in mitochondrial genomes (mtDNA) can cause various neurological and mitochondrial diseases such as mitochondrial myopathy, encephalopathy, lactic acidosis, stroke-like episodes (MELAS). Given the 16 kb length of mtDNA, continuous sequencing is feasible using long-read sequencing (LRS). Herein, we aimed to show a simple and accessible method for comprehensive mtDNA sequencing with potential diagnostic applications for mitochondrial diseases using the compact and affordable LRS flow cell "Flongle.

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  • * The study found that N-methylation of guanosine at position 9 (mG9) stabilizes wild-type mt-Leu(UAA) tRNA but destabilizes certain pathogenic variants associated with MELAS.
  • * Findings suggest that modifying the methylation level of mt-tRNAs could be a potential therapeutic approach for mt-tRNA-related diseases by impacting their stability and functionality.
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Purpose: To report a case of multifocal vitelliform lesions in a patient affected by metabolic encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) with the m.3243A>G variant.

Observations: A 37-year-old woman affected by MELAS was referred to our center for progressive vision deterioration.

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Article Synopsis
  • - MELAS syndrome is caused by a mitochondrial DNA mutation that affects the modification of tRNA, leading to problems with energy production in cells.
  • - This condition results in issues such as muscular weakness, brain dysfunction, increased lactic acid, and episodes resembling strokes.
  • - High-dose taurine supplementation has shown potential in clinical trials, helping to reduce stroke-like episodes and enhance cellular function in affected patients.
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Objective: To delineate the characteristics of stroke-like episodes (SLEs) in patients with adult-onset neuronal intranuclear inclusion disease (NIID) and to compare these characteristics with those of patients with MELAS.

Methods: Twenty-three adult-onset NIID patients who presented with acute or subacute brain disorders and 13 late-onset MELAS patients were enrolled in the study. Patients with NIID were categorized into the SLEs group and the encephalopathy-like episodes (ELEs) group according to the associated stroke-like lesions (SLLs) findings.

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  • This case report describes the first documented instance of a child having both mitochondrial encephalomyopathy (a condition affecting muscles and the brain) and nemaline myopathy (a muscle disorder), highlighting their coexistence.
  • An 11-year-old Sri Lankan boy, previously healthy, experienced acute neurological symptoms, elevated lactate levels, and imaging results indicative of an acute brain infarction, leading to genetic testing that confirmed both conditions.
  • The child's treatment included supportive care, antiepileptics, and supplements, with ongoing monitoring, underscoring the importance of genetic diagnosis for effective management and family counseling.
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Mitochondrial diseases (MtDs) present diverse clinical phenotypes, yet large-scale studies are hindered by their rarity. This retrospective, multicenter study, conducted across five Chinese hospitals' neurology departments from 2009 to 2019, aimed to address this gap. Nationwide, 1351 patients were enrolled, with a median onset age of 14.

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Mitochondrial DNA (mtDNA) mutations, including the m.3243A>G mutation that causes mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), are associated with secondary coenzyme Q (CoQ) deficiency. We previously demonstrated that PPARGC1A knockdown repressed the expression of PDSS2 and several COQ genes.

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[Clinical, imaging, and pathological characteristics of 35 cases of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome].

Zhonghua Nei Ke Za Zhi

July 2024

Department of Pathology,Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing 210008, China.

To summarize the clinical, imaging, and pathological characteristics of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS) to improve the diagnosis of this rare disease. A retrospective case series was conducted to collect the clinical data and results of genetic testing, muscle biopsy, and imaging studies including computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS) of 35 patients with MELAS admitted to the Nanjing Drum Tower Hospital from 2012 to 2021. Descriptive statistical analysis including mean, standard deviation, and frequency percentage were carried out.

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This study investigates transfer ribonucleic acid (tRNA) conformational dynamics in the context of MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) using solid-state silicon nitride (SiN) nanopore technology. SiN nanopores in thin membranes with specific dimensions exhibit high signal resolution, enabling real-time and single-molecule electronic detection of tRNA conformational changes. We focus on human mitochondrial tRNALeu(UAA) (mt-Leu(UAA)) that decodes Leu codons UUA/UUG (UUR) during protein synthesis on the mt-ribosome.

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Mitochondrial disease is a devastating genetic disorder, with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and m.3243A>G being the most common phenotype and genotype, respectively. The treatment for MELAS patients is still less effective.

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Lysosomal dysfunction and overload of nucleosides in thymidine phosphorylase deficiency of MNGIE.

J Transl Med

May 2024

Research Institute of Neuromuscular and Neurodegenerative Disease, Department of Neurology, Cheeloo College of Medicine, Qilu Hospital, Shandong University, West Wenhua Street No.107, Jinan, 250012, Shandong, China.

Inherited deficiency of thymidine phosphorylase (TP), encoded by TYMP, leads to a rare disease with multiple mitochondrial DNA (mtDNA) abnormalities, mitochondrial neurogastrointestinal encephalomyopathy (MNGIE). However, the impact of TP deficiency on lysosomes remains unclear, which are important for mitochondrial quality control and nucleic acid metabolism. Muscle biopsy tissue and skin fibroblasts from MNGIE patients, patients with m.

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Arginine Supplementation in MELAS Syndrome: What Do We Know about the Mechanisms?

Int J Mol Sci

March 2024

Division of Neurology, Department of Neurology and Neurosurgery, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil.

MELAS syndrome, characterized by mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes, represents a devastating mitochondrial disease, with the stroke-like episodes being its primary manifestation. Arginine supplementation has been used and recommended as a treatment for these acute attacks; however, insufficient evidence exists to support this treatment for MELAS. The mechanisms underlying the effect of arginine on MELAS pathophysiology remain unclear, although it is hypothesized that arginine could increase nitric oxide availability and, consequently, enhance blood supply to the brain.

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T cells have been shown to maintain a lower percentage (heteroplasmy) of the pathogenic m.3243A>G variant (MT-TL1, associated with maternally inherited diabetes and deafness [MIDD] and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes [MELAS]). The mechanism(s) underlying this purifying selection, however, remain unknown.

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Before blaming metformin as a trigger for stroke-like lesions in MELAS, alternative etiologies must be off the table.

Neurol Sci

July 2024

Biochemistry Laboratory, LR12ES05 "Nutrition-Functional Foods and Vascular Health", Faculty of Medicine, Monastir, Tunisia.

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Mitochondria are essential for human metabolic function. Over 350 genetic mutations are associated with mitochondrial diseases, which are inherited in a matrilineal fashion. In mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), defective mitochondrial function and resultant impaired cellular energy production compromise vascular perfusion in affected tissues.

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Rare causes of stroke-like presentations can be difficult to diagnose. We report a case of a man in his 40s who first presented with stroke symptoms, but whose clinical course was not typical for a stroke. A detailed investigation of the patient's medical history revealed bilateral sensorineural hearing loss which prompted a wider diagnostic assessment.

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Bilateral cochlear implants in a MELAS patient.

Eur Arch Otorhinolaryngol

June 2024

Department of Otolaryngology and Head Neck Surgery, MacKay Memorial Hospital, Taipei, Taiwan.

Background: Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a maternally inherited mitochondrial disease that affects various systems in the body, particularly the brain, nervous system, and muscles. Among these systems, sensorineural hearing loss is a common additional symptom.

Methods: A 42-year-old female patient with MELAS who experienced bilateral profound deafness and underwent bilateral sequential cochlear implantation (CIs).

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Renal manifestations in adults with mitochondrial disease from the mtDNA m.3243A>G pathogenic variant.

Nefrologia (Engl Ed)

December 2023

Serviço de Nefrologia, Centro Hospitalar e Universitário de São João, Porto, Portugal; Departamento de Medicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Grupo de Investigação e Desenvolvimento em Nefrologia e Doenças Infeciosas, I3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.

Mitochondrial diseases are a phenotype and genotype heterogeneous group of disorders that typically have a multisystemic involvement. The m.3243A>G pathogenic variant is the most frequent mitochondrial DNA defect, and it causes several different clinical syndromes, such as mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and the maternally inherited diabetes and deafness (MIDD) syndromes.

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Article Synopsis
  • MELAS is a genetic disorder affecting various body systems, caused by mitochondrial DNA mutations that lead to energy deficiencies, impacting organs like the brain and muscles.
  • The most common mutation linked to MELAS, m.3243A > G, significantly increases the risk of diabetes in affected individuals, with around 85% developing it by age 70.
  • A case of a 32-year-old Korean patient with MELAS shows worsened stroke-like episodes and lactic acidosis after taking metformin, raising questions about its safety in mitochondrial dysfunction.
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