-
Neuropathology : Official Journal of... Jun 2019We present an autopsied case with A8344G-mutated myoclonus epilepsy with ragged red fibers (MERRF)/mitochondrial encephalomyopathy with lactic acidosis and stroke-like...
We present an autopsied case with A8344G-mutated myoclonus epilepsy with ragged red fibers (MERRF)/mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) overlap syndrome accompanied by stroke-like episodes localized to the precentral gyrus. A 16-year-old Japanese woman suddenly experienced repetitive consciousness disturbances with increased serum lactate and creatine kinase levels. Magnetic resonance imaging showed abnormal intensity of bilateral precentral gyrus. She was clinically diagnosed as having a mitochondrial disorder and the A8344G mutation was detected in mitochondrial DNA. At 17 years of age, she died from congestive heart failure secondary to a third episode of lactic acidosis. Neuropatho-logically, multifocal laminar necrosis, which is responsible for stroke-like episodes in MELAS, was seen in the frontal cortex including the precentral gyrus, but there was no neuronal loss and gliosis in the basal ganglia, cerebellum, and brainstem, which were compatible with MERRF. Hypertrophy of the vascular smooth muscle and choroidal epithelium were seen, and were strongly visualized by an anti-mitochondrial antibody. Skeletal muscles showed uneven muscular diameters, increased central nuclei, and ragged red fibers (RRFs). Decreased cytochrome c oxidase (COX) activity and strongly succinate dehydrogenase (SDH)-reactive blood vessels were also noted. Stroke-like episodes in MERRF/MELAS overlap syndrome are thought to be rare in the frontal cortex including the precentral gyrus. Only two cases of MERRF/MELAS overlap syndrome with A8344G mutation, including this case, have shown stroke-like episodes in the frontal lobes. Other than the A8344G mutation and frontal lobe involvement, they had a high degree of similarity in terms of presence of RRFs, gastrointestinal dysfunction, and lack of typical MERRF neuropathology. In conclusion, this is an important case describing the clinical spectrum associated with A8344G-mutated MERRF/MELAS overlap syndrome.
Topics: Adolescent; Autopsy; Female; Frontal Lobe; Humans; MELAS Syndrome; MERRF Syndrome; Stroke
PubMed: 30972844
DOI: 10.1111/neup.12551 -
Zhonghua Bing Li Xue Za Zhi = Chinese... Apr 2019To investigate the ultrastructural features of muscle in patients with mitochondrial encephalomyopathy for its diagnosis and differential diagnosis. The clinical data...
To investigate the ultrastructural features of muscle in patients with mitochondrial encephalomyopathy for its diagnosis and differential diagnosis. The clinical data of 27 mitochondrial encephalomyopathy patients who underwent left or right biceps brachii muscle biopsy at Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University from July 2006 to August 2017 were analyzed retrospectively. The muscle biopsy specimens were examined underlight microscope and transmission electron microscope. There were 27 patients (17 males, 10 females) with an age range of 12 to 62 years (mean 29 years). The age of onset ranged from 3 to 38 years. The course of disease ranged from 1 month to 24 years. Twenty-two cases presented with lactic acidosis and stroke-like episodes (MELAS) syndrome, four with myoclonic epilepsy with ragged red fibers (MERRF) syndrome, and one with chronic progressive paralysis of extraocular muscle (CPEO) syndrome. Skeletal muscle biopsy showed abundant ragged red fibers and strongly SDH-reactive vessel. Genetic studies showed 17 of 22 cases of MELAS syndrome had A3243G mutation, and the other 5 cases had no abnormality. A8344G mutation was found in 3 of 4 cases of MERRF syndrome. No single or multiple mtDNA mutations were found in the single case of CPEO. Transmission electron microscopy of all 27 cases showed diffuse proliferation of mitochondria between the myofibrils and beneath the sarcolemma, with increased spacing between muscle cells. Seven cases showed numerous glycogen and four showed subsarcolemmal lipid droplets, 13 cases showed unusual mitochondrial morphology, including mitochondrial electron-dense substances and paracrystal line inclusions ("parking lot" change)in eight cases. Transmission electron microscopy shows significant differences in ultrastructural pathological changes among different patients with mitochondrial encephalomyopathy. Some patients with mild clinical symptoms have increased mitochondrial number, increased metabolism of glycogen and lipid droplets, while others with severe clinical symptoms have abnormal mitochondrial morphology. Typical crystalloid inclusions are found in mitochondria, which are of great value in the diagnosis of this disease.
Topics: Adolescent; Adult; Age of Onset; Child; Female; Humans; MELAS Syndrome; MERRF Syndrome; Male; Microscopy, Electron, Transmission; Middle Aged; Mitochondria, Muscle; Mitochondrial Encephalomyopathies; Muscle, Skeletal; Mutation; Retrospective Studies; Young Adult
PubMed: 30955266
DOI: 10.3760/cma.j.issn.0529-5807.2019.04.007 -
Chinese Medical Journal Apr 2019
Topics: Adult; DNA, Mitochondrial; Electroencephalography; Humans; MERRF Syndrome; Male; Mitochondrial Myopathies; Mutation; RNA, Transfer, Asn
PubMed: 30897601
DOI: 10.1097/CM9.0000000000000151 -
Frontiers in Neurology 2019Lipomas have often been associated with mtDNA mutations and were mainly observed in patients with mutation in mitochondrial tRNAlysine which is also the most frequent...
Lipomas have often been associated with mtDNA mutations and were mainly observed in patients with mutation in mitochondrial tRNAlysine which is also the most frequent mutation associated with MERRF. Up to date, no systematic studies have been developed in order to assess the incidence of lipomas in large cohorts of mitochondrial patients.The aim of this study is to analyze the incidence and characteristics of lipomas among an Italian cohort of patients with mitochondrial diseases. A retrospective, database-based study (Nation-wide Italian Collaborative Network of Mitochondrial Diseases) of patients with lipomas was performed. A total of 22 (1.7%) patients with lipomas have been identified among the 1,300 mitochondrial patients, enrolled in the Italian database. In about 18% multiple systemic lipomatosis (MSL) was the only clinical manifestation; 54% of patients showed a classical MERRF syndrome. Myopathy, alone or in association with other symptoms, was found in 27% of patients. Lactate was elevated in all the 12 patients in which was measured. Muscle biopsy was available in 18/22 patients: in all of them mitochondrial abnormalities were present. Eighty six percent had mutations in mtDNA coding for tRNA lysine. In most of patients, lipomas were localized along the cervical-cranial-thoracic region. In 68% of the patients were distributed symmetrically. Only two patients had lipomas in a single anatomical site (1 in right arm and 1 in gluteus maximum). MSL is often overlooked by clinicians in patients with mitochondrial diseases where the clinical picture could be dominated by a severe multi-systemic involvement. Our data confirmed that MSL is a rare sign of mitochondrial disease with a strong association between multiple lipomas and lysine tRNA mutations. MSL could be considered, even if rare, a red flag for mitochondrial disorders, even in patients with an apparently isolated MSL.
PubMed: 30873109
DOI: 10.3389/fneur.2019.00160 -
Chinese Medical Journal Mar 2019
Topics: Anticonvulsants; Clonazepam; Female; Humans; Levetiracetam; MERRF Syndrome; Male; Myoclonus
PubMed: 30807362
DOI: 10.1097/CM9.0000000000000042 -
Biochimica Et Biophysica Acta.... May 2019Mitochondrial diseases are a group of rare heterogeneous genetic disorders caused by total or partial mitochondrial dysfunction. They can be caused by mutations in...
Mitochondrial diseases are a group of rare heterogeneous genetic disorders caused by total or partial mitochondrial dysfunction. They can be caused by mutations in nuclear or mitochondrial DNA (mtDNA). MERRF (Myoclonic Epilepsy with Ragged-Red Fibers) syndrome is one of the most common mitochondrial disorders caused by point mutations in mtDNA. It is mainly caused by the m.8344A > G mutation in the tRNA (UUR) gene of mtDNA (MT-TK gene). This mutation affects the translation of mtDNA encoded proteins; therefore, the assembly of the electron transport chain (ETC) complexes is disrupted, leading to a reduced mitochondrial respiratory function. However, the molecular pathogenesis of MERRF syndrome remains poorly understood due to the lack of appropriate cell models, particularly in those cell types most affected in the disease such as neurons. Patient-specific induced neurons (iNs) are originated from dermal fibroblasts derived from different individuals carrying the particular mutation causing the disease. Therefore, patient-specific iNs can be used as an excellent cell model to elucidate the mechanisms underlying MERRF syndrome. Here we present for the first time the generation of iNs from MERRF dermal fibroblasts by direct reprograming, as well as a series of pathophysiological characterizations which can be used for testing the impact of a specific mtDNA mutation on neurons and screening for drugs that can correct the phenotype.
Topics: Adult; Cellular Reprogramming; Cellular Reprogramming Techniques; DNA, Mitochondrial; Dermis; Fibroblasts; Humans; MERRF Syndrome; Male; Middle Aged; Neurons; Point Mutation
PubMed: 30797798
DOI: 10.1016/j.bbamcr.2019.02.010 -
Polish Journal of Pathology : Official... 2018Our studies concerned skeletal muscle biopsy specimens from a patient with clinically suspected MERRF syndrome, confirmed by genetic tests showing the presence of point...
Our studies concerned skeletal muscle biopsy specimens from a patient with clinically suspected MERRF syndrome, confirmed by genetic tests showing the presence of point mutation in the m.8344A> G in the tRNALys gene. Ultrastructurally, extensive damage of mitochondria in skeletal muscle fibres was observed, including the presence of two types of mitochondrial inclusions. Mild damage of mitochondria was revealed in small blood vessels and the presence of calcium deposits in the vascular walls were observed. The differences in mitochondrial damage may be related to different origin and expenditure of biologically useful energy in these cells.
Topics: Humans; MERRF Syndrome; Microvessels; Mitochondria; Muscle Fibers, Skeletal; Mutation
PubMed: 30786693
DOI: 10.5114/pjp.2018.80904 -
Case Reports in Neurological Medicine 2018Mitochondrial (mt) tRNA (MTT) gene mutations are an important cause of mitochondrial diseases and are associated with a wide range of clinical presentations. Most...
Mitochondrial (mt) tRNA (MTT) gene mutations are an important cause of mitochondrial diseases and are associated with a wide range of clinical presentations. Most mutations fall into three mitochondrial tRNAs (tRNAIle, tRNALeu (UUR), and tRNALys) and are responsible for half of the mitochondrial diseasees associated with tRNA mutation, with MERRF, MELAS, mitochondrial myopathy, and Leigh syndrome being the most frequent phenotypes. More than 100 tRNA pathogenetic mutations are described, showing little correlation between the observed clinical phenotype and a specific mitochondrial tRNA mutation. Furthermore different mutation can manifest with similar clinical phenotypes, making the genotype-phenotype correlation difficult. Here we report the case of an Italian 53-year-old woman presenting with a proximal myopathy and the m.5835G>A mutation in MT-TY gene coding for the mitochondrial tRNA Tyrosine gene.
PubMed: 30643656
DOI: 10.1155/2018/8406712 -
European Annals of Otorhinolaryngology,... Apr 2019Patients with MERRF syndrome (Myoclonic Epilepsy with Ragged Red Fibres) usually present with encephalomyopathy. However, progressive, recurrent cervicothoracic...
INTRODUCTION
Patients with MERRF syndrome (Myoclonic Epilepsy with Ragged Red Fibres) usually present with encephalomyopathy. However, progressive, recurrent cervicothoracic lipomatosis may be rarely observed.
CASE REPORT
The authors report 4 cases of MERRF syndrome associated with lipomatosis. In 3 patients, the diagnosis of MERRF syndrome was established on the basis of the clinical features of the lipomas and clinical interview revealing a personal or family history of lipomas and myopathy.
DISCUSSION
In the presence of extensive spinal lipomatosis, the presence of other clinical signs of MERRF syndrome in the patient or the patient's family must be investigated. A diagnosis of MERRF syndrome can guide appropriate genetic counselling.
Topics: Adult; Female; Humans; Lipomatosis; MERRF Syndrome; Male; Middle Aged; Neck; Siblings; Spinal Neoplasms; Thorax
PubMed: 30409749
DOI: 10.1016/j.anorl.2018.10.015 -
Urology Case Reports Jan 2019
PubMed: 30364532
DOI: 10.1016/j.eucr.2018.10.006