Genetic Data Are a Prerequisite for Interpreting Clinical and Muscle Biopsy Findings in MELAS

No abstract available.

The Author Reply: Genetic Data Are a Prerequisite for Interpreting Clinical and Muscle Biopsy Findings in MELAS

No abstract available.

Twenty-one-year follow-up of variable onset MELAS syndrome with heteroplasmic nt3243A>G mtDNA mutation: A case report

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a maternally inherited mitochondrial disorder of which m.3243A>G is the most commonly associated mutation, resulting in an inability to meet the energy requirements of various organs. MELAS poses a diagnostic challenge owing to its multiple organ involvement and great clinical variability due to its heteroplasmic nature. We report three cases from a family who were initially misdiagnosed with myasthenia gravis or undiagnosed. Although there is no optimal consensus treatment approach for patients with MELAS because of the disease's heterogeneity, our 21-year-long therapy regimen of l-arginine, l-carnitine, and coenzyme Q10 supplementation combined with dietary management appeared to provide noticeable protection from the symptoms and complications. Prompt early diagnosis is important, as optimal multidisciplinary management and early intervention may improve outcomes.

Dexmedetomidine as a non-triggering anesthetic agent in a patient with MELAS syndrome and systemic sepsis: A case report

BACKGROUND: The selection of anesthetic agents is important in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome patient because serious and unexpected complications can occur after anesthetic exposure.CASE: A 30-year-old man with MELAS syndrome and sepsis underwent colectomy. Propofol was administered by step-wise until target effect-site concentration (Ce) 1.0 µg/ml and stopped for the loss of consciousness and to avoid hemodynamic instability. After the loss of consciousness, total intravenous anesthesia (TIVA) using dexmedetomidine (1.0 µg/ml/h) and remifentanil (1–4 ng/ml of Ce) was performed for the maintenance of anesthesia to avoid malignant hyperthermia and mitochondrial dysfunction. During the surgery, the bispectral index score stayed between 26 and 44, and increased to 97 after the end of anesthesia.CONCLUSIONS: TIVA with dexmedetomidine and remifentanil as non-triggering anesthetic agents in patients with MELAS syndrome and systemic sepsis may have advantages to decrease damages associated with mitochondrial stress and metabolic burden.

The Usefulness of Muscle Biopsy in Initial Diagnostic Evaluation of Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes

PURPOSE: The disease entity mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is characterized by an early onset of stroke-like episodes. MELAS is the most dominant subtype of mitochondrial disease. Molecular genetic testing is important in the diagnosis of MELAS. The mitochondrial DNA (mtDNA) 3243A>G mutation is found in 80% of MELAS patients. Nevertheless, molecular analysis alone may be insufficient to diagnose MELAS because of mtDNA heteroplasmy. This study aimed to evaluate whether muscle biopsy is useful in MELAS patients as an initial diagnostic evaluation method. MATERIALS AND METHODS: The medical records of patients who were diagnosed with MELAS at the Department of Pediatrics of Gangnam Severance Hospital between January 2006 and January 2017 were reviewed. The study population included 12 patients. They were divided into two subgroups according to whether the results of muscle pathology were in accordance with mitochondrial diseases. Clinical variables, diagnostic evaluations, and clinical outcomes were compared between the two groups. RESULTS: Of the 12 patients, seven were muscle pathology-positive for mitochondrial disease. No statistically significant difference in clinical data was observed between the groups that were muscle pathology-positive and muscle pathology-negative for mtDNA 3243A>G mutation. Additionally, the patients with weakness as the initial symptom were all muscle pathology-positive. CONCLUSION: The usefulness of muscle biopsy appears to be limited to an initial confirmative diagnostic evaluation of MELAS. Muscle biopsy can provide some information in MELAS patients with weakness not confirmed by genetic testing.

Targeted elimination of mutant mitochondrial DNA in MELAS-iPSCs by mitoTALENs

Mitochondrial diseases are maternally inherited heterogeneous disorders that are primarily caused by mitochondrial DNA (mtDNA) mutations. Depending on the ratio of mutant to wild-type mtDNA, known as heteroplasmy, mitochondrial defects can result in a wide spectrum of clinical manifestations. Mitochondria-targeted endonucleases provide an alternative avenue for treating mitochondrial disorders via targeted destruction of the mutant mtDNA and induction of heteroplasmic shifting. Here, we generated mitochondrial disease patient-specific induced pluripotent stem cells (MiPSCs) that harbored a high proportion of m.3243A>G mtDNA mutations and caused mitochondrial encephalomyopathy and stroke-like episodes (MELAS). We engineered mitochondrial-targeted transcription activator-like effector nucleases (mitoTALENs) and successfully eliminated the m.3243A>G mutation in MiPSCs. Off-target mutagenesis was not detected in the targeted MiPSC clones. Utilizing a dual fluorescence iPSC reporter cell line expressing a 3243G mutant mtDNA sequence in the nuclear genome, mitoTALENs displayed a significantly limited ability to target the nuclear genome compared with nuclear-localized TALENs. Moreover, genetically rescued MiPSCs displayed normal mitochondrial respiration and energy production. Moreover, neuronal progenitor cells differentiated from the rescued MiPSCs also demonstrated normal metabolic profiles. Furthermore, we successfully achieved reduction in the human m.3243A>G mtDNA mutation in porcine oocytes via injection of mitoTALEN mRNA. Our study shows the great potential for using mitoTALENs for specific targeting of mutant mtDNA both in iPSCs and mammalian oocytes, which not only provides a new avenue for studying mitochondrial biology and disease but also suggests a potential therapeutic approach for the treatment of mitochondrial disease, as well as the prevention of germline transmission of mutant mtDNA.

Atypical Radiologic Manifestation of NARP Mimicking MELAS: a Case Report

Neurogenic weakness, ataxia and retinitis pigmentosa (NARP) syndrome is a rare maternally inherited mitochondrial disorder. Radiologic findings in NARP syndrome are varied; they include cerebral and cerebellar atrophy, basal ganglia abnormalities, and on rare occasions, leukoencephalopathy. This article describes an extremely rare case of NARP syndrome mimicking mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).

Effects and Mechanisms of Taurine as a Therapeutic Agent

Taurine is an abundant, β-amino acid with diverse cytoprotective activity. In some species, taurine is an essential nutrient but in man it is considered a semi-essential nutrient, although cells lacking taurine show major pathology. These findings have spurred interest in the potential use of taurine as a therapeutic agent. The discovery that taurine is an effective therapy against congestive heart failure led to the study of taurine as a therapeutic agent against other disease conditions. Today, taurine has been approved for the treatment of congestive heart failure in Japan and shows promise in the treatment of several other diseases. The present review summarizes studies supporting a role of taurine in the treatment of diseases of muscle, the central nervous system, and the cardiovascular system. In addition, taurine is extremely effective in the treatment of the mitochondrial disease, mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and offers a new approach for the treatment of metabolic diseases, such as diabetes, and inflammatory diseases, such as arthritis. The review also addresses the functions of taurine (regulation of antioxidation, energy metabolism, gene expression, ER stress, neuromodulation, quality control and calcium homeostasis) underlying these therapeutic actions.

Evolução da disfagia em um caso de síndrome MELAS: o olhar dos cuidados paliativos / Dysphagia progression in a MELAS syndrome case: a palliative care perspective

RESUMO Este artigo teve por objetivo descrever a progressão da disfagia e a decisão pela via de alimentação em um caso de síndrome MELAS, sob o olhar dos cuidados paliativos. Trata-se de um caso do sexo feminino, que, por volta dos 26 anos de idade sofreu os primeiros sintomas da doença e teve sua função de deglutição progressivamente impactada. Foi realizado acompanhamento fonoaudiológico durante seis meses, com aplicação do protocolo de Avaliação da Segurança da Deglutição, da Functional Oral Intake Scale (FOIS) e gerenciamento da deglutição, com retornos ambulatoriais semanais e mensais. Em seis meses de seguimento, a paciente evoluiu de disfagia moderada a disfagia moderada a grave e variou entre os níveis 5 e 1 da FOIS. Manteve a alimentação por via oral, com restrição de consistências, manobra de deglutições múltiplas e controle de volume para ingestão de líquido, até que, ao final dos seis meses de seguimento, foi realizada gastrostomia. A alimentação por via oral em mais de uma consistência, porém com compensações, foi reduzida a uma alimentação exclusiva por via alternativa, ao longo do acompanhamento fonoaudiológico. Optou-se por manter a via oral de alimentação até a colocação da gastrostomia. A não sugestão de sonda nasoenteral se embasou no respeito à vontade da paciente e na possibilidade de alimentar-se, minimamente, de uma consistência por via oral.

ABSTRACT This article aims to describe a dysphagia progression and a choice of the feeding options in a case of MELAS syndrome, under the perspective of palliative care. It is a case in which a woman at the age of 26 years suffered the first symptoms of the disease and had the swallowing functionality progressively impacted. Speech-Language Therapy follow-up was performed at 6 months with the application of a swallowing safety assessment protocol, Functional Oral Intake Scale (FOIS) and swallowing management, with weekly and monthly outpatient returns. At six months of follow-up, the patient progressed from moderate dysphagia to moderate to severe dysphagia and ranged from levels 5 to 1 of FOIS. The patient maintained oral feeding with consistency restriction, dry swallowing maneuver, and control of volume for liquid intake until the end of the six months of follow-up, when gastrostomy was made. Oral feeding in more than one consistency but with compensations was reduced to exclusive non-oral feeding. We chose to maintain oral feeding until the gastrostomy was placed. Non-suggestion of nasoenteral tube was based on the patient's desire and the possibility of oral feeding in at least one food consistency.

Hallazgos radiológicos en sistema nervioso central (SNC) del síndrome de MELAS: reporte de caso / Radiological findings of MELAS syndrome in central nervous system (CNS): case report

RESUMEN Presentamos el caso clínico de una paciente adulta joven con episodios recurrentes sugestivos de ataque cerebrovascular, con cambios radiológicos típicos de enfermedad de MELAS con confirmación genética de mutación en el gen A3243G.

SUMMARY A clinical case of a young adult patient with recurrent episodes suggestive of stroke, with typical radiological changes of MELAS disease with genetic confirmation of mutation in A3243G gene.

Late-onset MELAS with Chronic Kidney Disease

Mitochondrial encephalomyopathy with lactic acid and stroke-like episodes (MELAS) is a multisystem mitochondrial disorder that typically presents in childhood. We report a case of MELAS syndrome diagnosed in a 45-year-old man presented with chronic kidney disease before a stroke-like episode. Genetic testing revealed a m.3243A>G point mutation in the mtDNA. The original diagnostic criteria for MELAS required the onset of stroke-like episodes prior to 40 years of age but this case demonstrates that disease onset may delay in certain individuals.

Acute Intestinal Pseudo-Obstruction in a Patient with MELAS Syndrome

No abstract available.

A Case of Atypical Leber Hereditary Optic Neuropathy Associated with MT-TL1 Gene Mutation Misdiagnosed with Glaucoma

PURPOSE: Leber hereditary optic neuropathy (LHON) is one of the most common hereditary optic neuropathies caused by mutations of mitochondrial DNA. Three common mitochondrial mutations causing LHON are m.3460, m.11778, and m.14484. We report a rare mutation of the mitochondrial tRNA (Leu [UUR]) gene (MT-TL1) (m.3268 A > G) in a patient with bilateral optic atrophy. CASE SUMMARY: A 59-year-old female diagnosed with glaucoma 3 years earlier at a community eye clinic presented to our neuro-ophthalmology clinic. On examination, her best corrected visual acuity was 0.4 in the right eye and 0.7 in the left eye, and optic atrophy was noticed in both eyes. Optical coherence tomography revealed retinal nerve fiber layer (RNFL) thinning in both eyes; average RNFL thickness was 52 µm in the right eye and 44 µm in the left eye, but the papillomacular bundle was relatively preserved in both eyes. Goldmann perimetry demonstrated peripheral visual field defects, mostly involving superotemporal visual field in both eyes. Mitochondrial DNA mutation test showed an unusual mutation in MT-TL1 gene seemingly related to this optic neuropathy. CONCLUSIONS: We found a rare mutation (m.3268 A > G) of the mitochondrial DNA in a patient having bilateral optic atrophy, which led to the diagnosis of LHON. There have been previous reports about mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and infantile myopathy caused by MT-TL1 mutation, but this is the first case of LHON associated with the same mutation. In this case of LHON associated with MT-TL1 mutation, atypical clinical features were observed with a relatively mild phenotype and peripheral visual field defects.

Case studies of two families with MIDD and MELAS: heteroplasmy level in m. 3243A>G mutation and the first report on m.3271T>C mutation in Colombia / Dos familias con midd y melas: nivel de heteroplasmia de la mutación m. 3243a>g y primer reporte de la mutación m.3271t>c en colombia

MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) and MIDD syndrome (maternally inherited diabetes and deafness) are mitochondrial diseases caused in most cases by the same mutation m.3243A> G, which affects the gene MT-TL1. The cases of two families with MELAS are presented here. In the first case, the m.3243A>G mutation was detected and the heteroplasmy level in blood, urine and oral mucosa were determined, finding a great phenotypic variability: the patient had higher heteroplasmy in the three tissues compared against oligosymptomatic relatives, and the mother had high blood sugar levels and hearing loss, suggesting a phenotype near to MIDD. In the second family, the m.3271T>C mutation was detected, which constitutes the first case reported in Colombia. These findings suggest that MIDD and MELAS, often described as distinct entities, are part of the same entity with variable expressivity partially depending on heteroplasmy.

El síndrome MELAS (encefalomiopatía mitocondrial, acidosis láctica y episodios similares a isquemia cerebral) y el síndrome MIDD (diabetes y sordera de herencia materna) son enfermedades mitocondriales producidas en la mayor parte de los casos por una misma mutación: la m.3243A>G que afecta al gen MT-TL1. Se presentan los casos de dos familias con MELAS. En la primera se detecta la mutación m.3243A>G y se determina el nivel de heteroplasmia en sangre, orina y mucosa oral, con lo que se evidencia una gran variabilidad fenotípica: la paciente tenía una mayor heteroplasmia en los tres tejidos en comparación con sus familiares oligosintomáticos y la madre tenía una glicemia elevada e hipoacusia, sugiriendo un fenotipo cercano al MIDD. En la segunda familia se detecta la mutación m.3271T>C, siendo el primer caso reportado en Colombia. Estos hallazgos sugieren que el MIDD y el MELAS, descritos frecuentemente como entidades distintas, hacen parte de una misma entidad con expresividad variable dependiendo en parte de la heteroplasmia.

MELAS en el Perú: reporte de caso / MELAS in Peru: case report

El síndrome de MELAS es una rara citopatía mitocondrial de difícil diagnóstico. Reportamos el caso de una niña de 10 años, que ingresó al Instituto Nacional de Ciencias Neurológicas de Lima, Perú, quien presentó episodios bruscos similares a accidentes cerebrovasculares y crisis epilépticas. Los estudios de neuroimágenes mostraron infartos y el examen genético fue positivo para MELAS identificando la mutación más frecuente A3243G...

MELAS syndrome is a rare mitochondrial cytopathy difficult to diagnose. We report the case of a 10 year old girl who was admitted to the National Institute of Neurological Sciences of Lima - Peru, who presented sudden stroke like episodes and seizures. Neuroimaging studies showed infarction and genetic testing was positive for identifying the most common MELAS mutation (A3243)...

When should MELAS (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes) be the diagnosis? / Quando o diagnóstico deveria ser MELAS (Miopatia mitocondrial, encefalopatia, acidose lática, e episódios semelhantes a acidente vascular cerebral)?

ABSTRACTMitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) is a rare mitochondrial disorder. Diagnostic criteria for MELAS include typical manifestations of the disease: stroke-like episodes, encephalopathy, evidence of mitochondrial dysfunction (laboratorial or histological) and known mitochondrial DNA gene mutations. Clinical features of MELAS are not necessarily uniform in the early stages of the disease, and correlations between clinical manifestations and physiopathology have not been fully elucidated. It is estimated that point mutations in the tRNALeu(UUR) gene of the DNAmt, mainly A3243G, are responsible for more of 80% of MELAS cases. Morphological changes seen upon muscle biopsy in MELAS include a substantive proportion of ragged red fibers (RRF) and the presence of vessels with a strong reaction for succinate dehydrogenase. In this review, we discuss mainly diagnostic criterion, clinical and laboratory manifestations, brain images, histology and molecular findings as well as some differential diagnoses and current treatments.

RESUMOMiopatia mitocondrial, encefalopatia, acidose lática, e episódios semelhantes a acidente vascular cerebral (MELAS) é uma rara doença mitocondrial. Os critérios diagnósticos para MELAS incluem as manifestações típicas da doença: episódios semelhantes a acidente vascular cerebral, encefalopatia, evidência de disfunção mitocondrial (laboratorial ou histológica) e mutação conhecida em genes do DNA mitocondrial. Na fase inicial da doença, as manifestações clínicas podem não ser uniformes, e sua correlação com a fisiopatologia não está completamente elucidada. Estima-se que as mutações de ponto no gene tRNALeu(UUR) do DNAmt, principalmente a A3243G, sejam responsáveis por cerca de 80% dos casos de MELAS. As alterações morfológicas na biópsia muscular incluem uma grande proporção de fibras vermelhas rasgadas (RRF) e presença de vasos com forte reação para succinato desidrogenase. Nesta revisão, são discutidos os principais critérios diagnósticos, manifestações clínicas e laboratoriais, imagens cerebrais, padrões eletrofisiológicos, histológicos e alterações moleculares, bem como alguns dos diagnósticos diferenciais e tratamentos atuais.

Encefalomiopatía mitocondrial, acidosis láctica y episodios de accidente cerebrovascular, síndrome de MELAS. Reporte de un caso clínico / Mitochondrial encephalomyopathy lactic acidosis and stroke like episodes MELAS syndrome. Report of a clinical case

Las enfermedades mitocondriales producen una serie de desórdenes neurológicos que se heredan por parte materna, el síndrome de MELAS es considerado un raro desorden multisistémico neurodegenerativo de muy mal pronóstico, posee una incidencia de 16,3/100 000 casos, este síndrome se manifiesta antes de los 40 años, caracterizado por cuadros convulsivos, alteración del estado de conciencia, acidosis láctica, y accidentes cerebrovasculares, estas manifestaciones suelen ser evidentes en los estadíos avanzados, lo que dificulta su diagnóstico; siendo necesario un equipo multidisciplinario, donde los estudios de laboratorio y las técnicas imagenológicas juegan un papel fundamental. Les presentamos el caso de un paciente masculino de 29 años que acudió a emergencia del Hospital Central de Mendoza-Argentina con antecedentes de madre y hermana fallecidas. Tanto la tomografía como la resonancia magnética evidenciaron zonas infartadas de localización temporo-parieto-occipital, acompañado de calcificaciones en los núcleos basales, llegando al diagnóstico de síndrome de MELAS, para el cual no existe un tratamiento definitivo sólo paliativo

Mitochondrial diseases are neurological disorders that are inherited maternally, the MELAS syndrome is considered a rare multisystem neurodegenerative disorder with a poor prognosis, has an incidence of 16,3 / 100 000 cases, this syndrome is manifested before age 40 years, characterized by convulsive, altered state of consciousness, lactic acidosis, and stroke, these manifestations are usually evident in advanced stages, making it difficult to diagnosis; being necessary equipment multi-disciplinary where laboratory studies and imaging techniques play a fundamental role. We present the case of a male patient of 29 years, who attended in Emergency of Hospital Central Mendoza-Argentina with a history of mother and sister dead. Both Computed tomography and Magnetic resonance showed infarcted areas with localization temporo-parieto-occipital, accompanied by calcifications in the basal nuclei, reaching the diagnosis of MELAS. for this syndrome there is not definitive treatment, only palliative.

A Case of MELAS Syndrome Presenting with Type 1 Diabetes Mellitus / 대한내과학회지

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome presents with various clinical features, including seizures, stroke-like episodes, encephalopathy, myopathy, cardiac involvement, and diabetes. However, due to its clinical heterogeneity, the diagnosis of MELAS syndrome is complex and difficult. The present report describes an 18-year-old male who was diagnosed with MELAS syndrome following the onset of type 1 diabetes. The patient had suffered from ataxia, mental retardation, and recurrent headaches for several years; following hospitalization for loss of consciousness, he was treated for cerebellar atrophy and Wolf-Parkinson-White (WPW) syndrome. Although the patient had no history of lactic acidosis, the recent onset of type 1 diabetes and his medical history of encephalopathy and WPW syndrome suggested MELAS syndrome. The diagnosis of MELAS syndrome was confirmed by molecular genetic testing, which revealed a point mutation (A3243G) in the patient's mitochondrial DNA.