Lethal mitochondrial trifunctional protein deficiency caused by HADHB gene variation: a case report / 中华围产医学杂志

This article reported a male neonate with lethal mitochondrial trifunctional protein deficiency (MTPD) caused by compound heterozygous variations in the HADHB gene. The patient presented with poor milk intake complicated by abnormal myocardial enzymes within 24 h after birth and was transferred to the Children's Hospital of Nanjing Medical University on day 4. Physical examination revealed no obvious abnormalities on admission. Laboratory examination showed increased creatine kinase isoenzyme and cardiac troponin levels, and electrocardiogram suggested sinus tachycardia and low QRS voltage in limb leads. Blood screening for metabolic abnormalities showed high levels of tetradecenyl carnitine and various 3-hydroxycarnitines. Heterozygous mutations of c.739C>T(p.Arg247Cys) and c.607C>T(p.Arg203Ter,272) were detected in the HADHB gene in the boy, which were pathogenic variants included in the Human Gene Mutation Database. Followed up to three months of age, the boy was readmitted to hospital due to poor milk intake for one week and poor response for 2 d after catching a cold. After admission, he quickly developed multiple organs dysfunction such as heart failure and respiratory failure, and then died. Lethal MTPD is rare with no effective treatment and poor prognosis. Lethal MTPD should be highly suspected when unexplained cardiomyopathy, hypoglycemia, acidosis and other metabolic abnormalities appear in the neonatal period, and an early diagnosis could be confirmed with genetic testing in the neonatal period.

Miopatia mitocondrial e deficiência auditiva neurossensorial: estudo de caso / Mitochondrial myopathy and sensorineural hearing loss: case study

Resumo A miopatia mitocondrial é causada pela ausência e/ou insuficiência de uma enzina quaternária, L-carnitina, responsável por transportar ácidos graxos livres para a parte interna da mitocôndria. A função da mitocôndria é produzir energia, contribuindo para o bom funcionamento das células. A Lipidose Muscular é uma doença que provoca anomalias em enzimas que metabolizam gordura e por consequência causa acúmulo de toxinas de subprodutos com gordura nos tecidos. O objetivo deste trabalho é apresentar o estudo de caso da paciente B.D., 37 anos, diagnosticada com Lipidose Muscular aos seis anos, com deficiência de L-Carnitina e relatar o acompanhamento fonoaudiológico realizado em um serviço de saúde auditiva. A abertura de prontuário da paciente foi realizada em 05/03/1989. Foi prescrito pelo neurologista o uso contínuo de 2g/dia de L-carnitina. A mãe relatou que B.D. apresentava dificuldades em ouvir, pois era muito desatenta, o que foi mais evidente quando começou a frequentar a escola. Em 1988, a paciente foi diagnosticada com perda auditiva neurossensorial de grau moderado bilateral e começou a fazer uso de aparelhos de amplificação sonora individual retroauriculares em 1989. O desempenho escolar e comunicação melhoraram. Em 1998, passou a utilizar aparelhos tipo micro canal, o que a favoreceu esteticamente, promoveu melhora da localização sonora e maior ganho em altas frequências. Os limiares de audibilidade apresentaram uma leve piora e a paciente atualmente é pós-graduada e trabalha em uma grande instituição financeira. Conclui-se que o diagnostico neurológico e a intervenção fonoaudiológica precoces possibilitaram o adequado desenvolvimento de linguagem da paciente.

Abstract Mitochondrial myopathy is caused by the absence and/or insufficiency of L-carnitine, a quaternary enzyme responsible for transporting free fatty acids into the mitochondria. The primary function of the mitochondria is to produce energy, contributing to proper cell functioning. Muscular lipidosis causes abnormalities in enzymes that metabolize fat, resulting in the accumulation of harmful amounts of fats in tissues. The aim of this study was to present the case study of patient B.D., a 37-year-old woman diagnosed with muscular lipidosis with L-carnitine deficiency at 6 years old, and describe the speech-language follow-up performed at a hearing care clinic. The first entry in the patient's medical chart was on 03/05/1989, with continuous use of 2g/day of L-carnitine prescribed by a neurologist. The mother reported that B.D. had difficulty hearing and was inattentive, which became more evident when she started school. In 1988 the patient was diagnosed with moderate bilateral sensorineural hearing loss and began using behind-the-ear (BTE) hearing aids in 1989, after which her academic performance and communication improved. In 1998 she switched to Completely in Canal (CIC) hearing aids, which are more discreet, provided better sound localization and greater high frequency gain, although her hearing thresholds worsened slightly. She completed her graduate studies and currently works at a large financial institution. It was concluded that early neurological diagnosis and speech-language intervention enabled adequate language development in the patient.

Neumopatía crónica secundaria al trastorno de la deglución en un paciente con miopatía mitocondrial / Chronic pneumopathy secondary to swallowing disorder in a patient with mitochondrial myopathy

RESUMEN Introducción: la enfermedad pulmonar crónica secundaria a la disfagia es una complicación frecuente en los pacientes con enfermedades neuromusculares. Las miopatías mitocondriales son un conjunto de enfermedades que pueden conducir a daño pulmonar progresivo, secundario al síndrome aspirativo crónico. Caso clínico: niño de 7 años con signos clínicos y radiológicos de enfermedad pulmonar crónica; además, con desnutrición crónica, debilidad muscular, disfonía y oculoparesia externa crónica multiplanar. Su padre tuvo síntomas similares desde la infancia y requirió alimentación con dieta espesa por trastorno de la deglución. Se confirma en el paciente la presencia de disfagia como la causa de la neumopatía crónica y se sospecha miopatía congénita hereditaria. En consecuencia, se realiza el diagnóstico de enfermedad mitocondrial con oculoparesia externa crónica, mediante la secuenciación del gen polimerasa gamma del ADN mitocondrial (POLG). Conclusiones: en los pacientes con neumopatía crónica se deben considerar las enfermedades neuromusculares en el diagnóstico diferencial. La miopatía mitocondrial con oculoparesia externa crónica progresiva, se asocia con trastorno de la deglución hasta en un 50 % de los casos. El diagnóstico temprano es importante para retardar el deterioro de la función pulmonar.

SUMMARY Introduction: Chronic lung disease secondary to dysphagia is a frequent complication in patients with neuromuscular diseases. Mitochondrial myopathies could lead to progressive lung damage due to chronic aspiration syndrome. Clinical case: Seven-year-old male with clinical and radiological signs of chronic lung disease, as well as low weight, weakness, dysphonia and multiplanar external oculoparesis. His father had similar symptoms during infancy and needed thickened liquid diet due to swallowing disorder. Dysphagia was confirmed as the cause of chronic lung disease and, therefore, hereditary congenital myopathy was suspected. Mitochondrial disease with chronic external oculoparesis was confirmed by molecular sequencing of the mitochondrial DNA gamma polymerase gene (POLG). Conclusion: Neuromuscular disorders may cause chronic lung disease. Mitochondrial myopathy with progressive chronic external oculoparesis is associated with swallowing disorder in 50 % of the cases. Early diagnosis is important to slow decline in lung function.

Quantitation of muscle pathology abnormalities in 18 patients with mitochondrial disorders / Quantificação das anormalidades patológicas musculares em 18 pacientes com desordens mitocondriais

ABSTRACT INTRODUCTION: Mitochondrial disorders can lead to the accumulation of mitochondria in muscle fibers, as indicated by ragged red (RRF) or ragged blue fibers when stained with modified Gomori trichrome or succinate dehydrogenase (SDH+), respectively, and, absence of activity of cytochrome c oxidase, COX negative fibers (COX-). The combined COX-SDH stain (COMBO+) can reveal even more COX-deficient fibers. OBJECTIVE: To quantify RRFs, SDH+, COX-, and COMBO+ fibers in muscle biopsies with mitochondrial findings. MATERIAL AND METHODS: We retrospectively selected 18 muscle biopsies with mitochondrial abnormalities based on the Walker criteria (percentage of RRFs/COX- fibers, and clinical picture), and/or the Sleigh criteria (percentage of RRFs, SDH+, and COX- fibers). RESULTS: Females represented 83.3%, with a mean age of 38.6 years (5 months-70 years). Patients were diagnosed with chronic progressive external ophthalmoplegia (CPEO, 66.7%), proximal myopathy (22.2%), idiopathic hyperCKemia (11.1%), Kearns-Sayre syndrome (5.6%), mitochondrial encephalomyopathy with ragged red fibers and stroke-like episodes (5.6%), and a dystrophic pattern (5.6%). Some cases of CPEO were combined with proximal myopathy. The quantitative pathologic findings were: RRFs, 3.95% ± 3.17%; SDH+, 7.55% ± 6.1%; COX-, 10.9% ± 7.2%; COMBO+, 14.22% ± 12.79%. We found a slight variation in the diameter of muscle fibers, no necrosis or proliferative connective tissue, few fibers with internal nuclei, and some cases with fiber type grouping. CONCLUSION: Pathologic events, grouped in ascending order of frequency, were RRFs, SDH+ fibers, COX- fibers, and COMBO+ fibers. These data emphasize the importance of the COMBO technique in revealing occult COX deficiency in muscle fibers.

RESUMO INTRODUÇÃO: Desordens mitocondriais são usualmente caracterizadas por: 1. acúmulo de mitocôndria nas fibras musculares que aparecem como fibras vermelhas rasgadas (FVR) ou azuis rasgadas quando coradas, respectivamente, pelo tricrômio modificado de Gomori ou pelo succinato desidrogenase (SDH+); 2. ausência de atividade da citocromo c oxidase (COX), originando fibras COX negativa (COX-). A combinação de colorações COX e SDH pode revelar ainda mais fibras COX deficiente (COMBO+). Objetivos: Quantificar FVR, SDH+, COX- e COMBO+ em biópsias musculares com anormalidades mitocondriais. MATERIAL E MÉTODOS: Foram analisadas retrospectivamente 18 biópsias com anormalidades mitocondriais com base no critério de Walker (percentagem de FVR/ COX- e quadro clínico) e/ou critério de Sleigh (percentagem de FVR, SDH+ e COX-). RESULTADOS: Sexo feminino representou 83, 3% e média de idade 38, 6 anos (5 meses a 70 anos). Oftalmoplegia externa progressiva crônica (OEPC) representou 66, 7%; miopatia proximal, 22, 2%; hiperCKemia idiopática, 11, 1%; síndrome de Kearns-Sayre, 5, 6%; encefalopatia mitocondrial com FVR e episódios semelhantes a acidente vascular cerebral, 5, 6%; e padrão distrófico, 5, 6%. Alguns casos de OEPC estavam associados à miopatia proximal. Achados patológicos quantitativos: FVR, 3, 95% ± 3, 17%; SDH+, 7, 55% ± 6, 1%; COX-, 10, 9% ± 7, 2%; COMBO+, 14, 22% ± 12, 79%. Encontramos leve variação de calibre das fibras musculares sem necrose ou proliferação de tecido conjuntivo, poucas fibras com núcleos internos e alguns casos com agrupamento de fibras. CONCLUSÃO: As anormalidades patológicas nas fibras musculares em ordem ascendente de frequência foram: FVR, SDH+, COX- e COMBO+. Nossos achados enfatizam a importância da técnica COMBO (COX + SDH) para aumento na frequência de fibras musculares COX deficiente ocultas.

The Newcastle Pediatric Mitochondrial Disease Scale: translation and cultural adaptation for use in Brazil / Escala Pediátrica de Doença Mitocondrial de Newcastle: tradução e adaptação cultural para uso no Brasil

ABSTRACT Objective The aim of this study was to translate and adapt the Newcastle Paediatric Mitochondrial Disease Scale (NPMDS) to Portuguese for use in Brazil. Methods The scale was applied in 20 pediatric patients with mitochondrial disease, in three groups: myopathy (n = 4); Leigh syndrome (n = 8); and encephalomyopathy (n = 8). Scores were obtained for the various dimensions of the NPMDS, and comparisons were drawn between the groups. Results There was a statistically significant difference between the myopathy group and the Leigh syndrome group (p = 0.0085), as well as between the myopathy and encephalomyopathy groups (p = 0.01). Conclusions The translation of the NPMDS, and its adaptation to the socioeconomic and cultural conditions in Brazil, make the NPMDS score useful as an additional parameter in the evaluation and monitoring of pediatric patients with MD in Brazil.

RESUMO Objetivo O objetivo do presente estudo foi realizar a tradução e adaptação da escala NPMDS para a população brasileira. Métodos A escala foi aplicada em 20 crianças e adolescentes com doença mitocondrial (DM) divididos em três grupos: miopatia (n=4), síndrome de Leigh (n=8) e encefalomiopatia (n=8). Obteve-se os escores separados das dimensões da escala NPMDS, foram realizadas comparações entre os escores da NPMDS nos diferentes grupos. Conclusão A tradução da escala NPMDS e sua adequação as condições socioeconômicas e culturais de nossa população tornam este instrumento um parâmetro adicional na avaliação e acompanhamento de pacientes pediátricos com DM.

Obstetric anesthesia considerations in Kearns-Sayre syndrome: a case report / 대한마취과학회지

Kearns-Sayre syndrome (KSS) is a rare mitochondrial myopathy that usually develops before 20 years of age. It demonstrates multisystemic involvement with a triad of cardinal features: progressive ophthalmoplegia, pigmentary retinopathy, and cardiac conduction abnormalities. In addition, patients might have cerebellar ataxia, a high content of protein in the cerebrospinal fluid, proximal myopathy, multiple endocrinopathies, and renal tubular acidosis. We herein report the successful obstetric analgesic and anesthetic management of a 28-year-old parturient patient with KSS who required labor analgesia and proceeded to deliver by cesarean section. We extrapolate that regional analgesia/anesthesia might be beneficial for reducing the metabolic demands associated with the stress and pain of labor in patients with KSS. Efficient postoperative analgesia should be provided to decrease oxygen requirements.

Obstetric anesthesia considerations in Kearns-Sayre syndrome: a case report / 대한마취과학회지

Kearns-Sayre syndrome (KSS) is a rare mitochondrial myopathy that usually develops before 20 years of age. It demonstrates multisystemic involvement with a triad of cardinal features: progressive ophthalmoplegia, pigmentary retinopathy, and cardiac conduction abnormalities. In addition, patients might have cerebellar ataxia, a high content of protein in the cerebrospinal fluid, proximal myopathy, multiple endocrinopathies, and renal tubular acidosis. We herein report the successful obstetric analgesic and anesthetic management of a 28-year-old parturient patient with KSS who required labor analgesia and proceeded to deliver by cesarean section. We extrapolate that regional analgesia/anesthesia might be beneficial for reducing the metabolic demands associated with the stress and pain of labor in patients with KSS. Efficient postoperative analgesia should be provided to decrease oxygen requirements.

Genetics of Mitochondrial Myopathies

Mitochondrion is an intracellular organelle with its own genome. Its function in cellular metabolism is indispensable that mitochondrial dysfunction gives rise to multisystemic failure. The manifestation is most prominent with tissues of high energy demand such as muscle and nerve. Mitochondrial myopathies occur not only by mutations in mitochondrial genome, but also by defects in nuclear genes or secondarily by toxic insult on mitochondrial replication. Currently curative treatment modality does not exist and symptomatic treatment remains mainstay. Administration of L-arginine holds great promise according to the recent reports. Advances in mitochondrial RNA import might enable a new therapeutic strategy.

Anesthetic Management of a Patient with Mitochondrial Myopathy Undergoing Orthopedic Surgery

Mitochondria myopathies consist of large heterogeneous groups of disorders resulting from primary dysfunction of the mitochondrial respiratory chain and causing muscle disease. These disorders involve the multiple organ system and appear to be extensive variability in clinical presentation. Therefore anesthetic management of patients with mitochondrial myopathies should begin with careful preoperative investigation and preparation. We report successful general anesthesia in a 22-year-old man with mitochondrial myopathy undergoing orthopedic surgery.

A Case of Early Onset MELAS Patient with Wolff-Parkinson-White Syndrome / 대한소아신경학회지

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the classic mitochondrial diseases characterized by symptoms of repeated episodes of hemiparesis with mitochondrial DNA mutation. We report a rare case of early onset MELAS patient confirmed by genetic analysis with Wolff-Parkinson-White syndrome.

MELAS: clinical features, muscle biopsy and molecular genetics / MELAS: manifestações clínicas, biópsia muscular e estudo molecular

OBJECTIVE: The aim of the study was to analyze a series of Brazilian patients suffering from MELAS. METHOD: Ten patients with MELAS were studied with correlation between clinical findings, laboratorial data, electrophysiology, histochemical and molecular features. RESULTS: Blood lactate was increased in eight patients. Brain image studies revealed a stroke-like pattern in all patients. Muscle biopsy showed ralled-red fibers (RRF) in 90 percent of patients on modified Gomori-trichrome and in 100 percent on succinate dehydrogenase stains. Cytochrome c oxidase stain analysis indicated deficient activity in one patient and subsarcolemmal accumulation in seven patients. Strongly succinate dehydrogenase-reactive blood vessels (SSV) occurred in six patients. The molecular analysis of tRNA Leu(UUR) gene by PCR/RLFP and direct sequencing showed the A3243G mutation on mtDNA in 4 patients. CONCLUSION: The muscle biopsy often confirmed the MELAS diagnosis by presence of RRF and SSV. Molecular analysis of tRNA Leu(UUR) gene should not be the only diagnostic criteria for MELAS.

OBJETIVO: O objetivo deste estudo foi analisar uma série de pacientes brasileiros portadores de MELAS. MÉTODO: Dez pacientes com MELAS foram estudados com correlação entre manifestações clínicas, alterações laboratoriais, estudo eletrofisiológico, histoquímico e molecular. RESULTADOS: O nível de lactato sérico estava aumentado em 8 pacientes. O estudo das imagens do crânio revelou padrão semelhante ao de AVC isquêmico em todos os pacientes. A biópsia muscular mostrou fibras rajadas vermelhas (RRF) em 90 por cento dos pacientes na coloração pelo tricrômio de Gomori modificado e em 100 por cento na reação histoquímica pela desidrogenase succicínica (SDH). A análise da coloração pela citocromo c oxidase indicou atividade deficiente em um paciente e acúmulo subsarcolemal em sete pacientes. Vasos com forte reação para SDH (SSV) ocorreram em seis pacientes. O estudo molecular do gene tRNA Leu(UUR) por PCR/RLFP e seqüenciamento direto mostrou a mutação A3243G no DNAmt de 4 pacientes. CONCLUSÃO: A biópsia muscular frequentemente confirma o diagnóstico de MELAS pela presença de RRF e SSV. O estudo molecular do gene tRNA Leu(UUR) não deve ser o único critério diagnóstico para MELAS.

Transposição da rima palpebral em ptose miogênica mitocondrial / Tarsal switch levator for mitochondrial myogenic ptosis

OBJETIVO: Relatar o uso da ressecção do tarso da pálpebra superior e enxerto na pálpebra inferior para a elevação da rima palpebral e liberação do eixo visual, sem causar complicações corneanas em pacientes portadores de ptose miogênica mitocondrial. MÉTODOS: Estudo prospectivo. A técnica cirúrgica consiste na tarsectomia da pálpebra superior e autoenxerto do tarso na lamela posterior da pálpebra inferior. As cirurgias foram realizadas sob anestesia local. No caso de diplopia, a cirurgia foi realizada em apenas um olho. RESULTADOS: O procedimento foi realizado em 9 olhos de 6 pacientes com miopatia mitocondrial. Cinco pacientes eram do sexo feminino, a média de idade foi de 59,8 anos e o seguimento variou de 30 a 60 meses. A rima palpebral elevou em todos os pacientes, descobrindo o eixo visual na posição primária do olhar e melhorando a posição viciosa de cabeça. Não houve complicações decorrentes da exposição do globo ocular. CONCLUSÃO: A técnica de transposição da rima palpebral é útil na correção do mau posicionamento das pálpebras em pacientes sem mecanismos de proteção porque eleva a pálpebra superior e a inferior, diminuindo ou eliminando o risco de causar lagoftalmo com complicações corneanas.

PURPOSE: To report the use of tarsal switch levator resection procedures that lift the palpebral fissure to visual axis without causing corneal complications in patients with mitochondrial myogenic ptosis. METHODS: Prospective study. The technique consists of an upper eyelid tarsectomy, with transfer of the autologous tarsoconjunctival graft to the posterior lamella of the lower eyelid. The surgeries were performed under local anesthesia. In case of diplopia, the surgery was performed in one eye. RESULTS: Tarsal switch procedure was performed in 9 eyes of 6 patients with mitochondrial myopathy. There were 5 women; the average age was 59.8 years and the follow-up ranged from 30 to 60 months. The palpebral fissure was moved cephalad in all patients, unmasking their visual axis in primary position and improving their head position. There was no patient with exposure symptoms after surgery. CONCLUSION: The tarsal switch procedure is useful in managing the eyelid malpositions in patients with poor eye protective mechanisms because it elevates both the upper and the lower eyelids, decreasing or eliminating the risk of lagophthalmos with corneal complications.

A study on the expression of anti-mitochondriai antibody in the brain of patients with MELAS syndrome / 中华内科杂志

Objective To investigate the pathological changes and pathogenesis of the MELAS syndrome (mitochondrial encephalopathy lactic acidosis strok-like episodes ) by using the method of immunohistochemical staining in the brain biopsy specimens with anti-mitochondrial antibody (AMA).Methods We performed immunohistochemical staining in 3 confirmed MELAS patients' paraffin-imbed brain biopsy specimens.Results Small vessel proliferation and the uneven thickness of the wall were found in the 3 MELAS patients.A lot of brown deposits was shown in the wall of small vessels and also noted in neurons.Conclusions The main pathological change in the MELAS brain biopsy immunohistochemical staining with AMA was the small vessel proliferation,indicating that abnormal mitochondria accumulated in the vascular smooth muscle,endothelial cell and neurons of the lesion sites.This finding was consistent with the electron microscopic discovery and valuable for the diagnosis of MELAS.

Myopathy due to Chronic Clevudine Therapy: A Case Report

A 40-year-old man with chronic hepatitis B complained of progressive weakness of the proximal muscles and edema of both legs. He had been receiving long-term clevudine (nucleoside analogue reverse transcriptase inhibitor, NRTI) therapy for his hepatitis. The serum creatine kinase level was increased on the laboratory tests. His electromyography showed a generalized myopathic process. The muscle biopsy showed numerous ragged-red fibers, degenerating myofibers with variable sized cytoplasmic bodies, the prominence of type 1 fibers with type 2 fiber atrophy and an endomysial mononuclear cell infiltration. The electron microscopic examination revealed necrotic myofibers, including extremely dysmorphic mitochondria with extensive loss, blunting and focal clumping of the cristae and concentric cristae. Although clevudine is known to be a less cytotoxic agent among the various NRTIs, careful clinical attention should be paid to the patients who are receiving long-term clevudine therapy for the occurrence of myopathy.

Síndrome de Kearns-Sayre / Kearns-Sayre syndrome

A síndrome de Kearns-Sayre é uma patologia rara, que acarreta piora da qualidade de vida; caracteriza-se por oftalmoplegia externa progressiva, fraqueza muscular e distúrbios na condução cardíaca. A entidade integra um grupo de desordens do metabolismo mitocondrial, denominadas miopatias mitocondriais ou citopatias mitocondriais.

Kearns-Sayres syndrome is a rare pathology which leads to a worse quality of life of the individual; it is characterized by progressive external ophthalmoplegia, muscular weakness, and cardiac conduction defects. The disease belongs to a group of mitochondrial metabolic disorders, named mitochondrial myopathies of mitochondrial cytopathies.

A Case of Mitochondrial Myopathy With Cardiac Involvement

Mitochondrial myopathy is a disease caused by structural, biochemical or genetic disturbance of the mitochondria and this affects many organs, and it may also involve the cardiac muscles. We experienced a case of myocardial involvement in a 21 years old male patient with mitochondrial myopathy.

Auxiliary diagnosis of aerobic forearm exercise in mitochondriai myopathy and encephalopathy / 中华神经科杂志

Objective To investigate blood gas analysis and lactic acid evaluation in aerobic forearm exercise and the significance of aerobic forearm exercise for the auxiliary diagnosis of mitochondrial myopathy and encephalopathy patients.Methods Forty-two patients with mitochondrial myopathy and encephalopathy patients, 40 healthy control, and 40 patients control were studied.They performed a protocol under aerobic exercise conditions, consisting of intermittent forearm exercise for 4 minutes at 40% of intented maximal voluntary contraction force.Blood samples were collected to monitor blood gas and plasma lactate before, during arid after exercise.Results During exercise venous PO_2(mm Hg, 1 mm Hg=0.133 kPa)decreased in mitochondrial myopathy and encephalopathy patients from 41.2?12.6 to 39.5?16.2, whereas PO_2 fell from 50.5?14.4 to 30.8?13.1 in healthy control and from 50.1?7.9 to 44.3?35.5 in patient control.Venous PO_2 decreased much more in healthy control group than the other 2 groups(F= 6.34,P

Clinical and pathological studies on two cases of mitochondrial enteromyopathy / 中华神经科杂志

Objective To report two cases of mitochondrial disease presenting with marked gastrointestinal symptoms and mild myopathy without involvement of central nerve system as to investigating the diagnostic rules of the disease Methods Case 1 is a 13 year old boy who had suffered from recurrent vomiting with mild diarrhea and fatigue for 7 years Physical examination showed mild weakness of both legs without ophthalmoplegia and cognitive defects Radiological examination revealed gastroptosis with excessive peristalsis of small intestine Case 2 is of a 6 year old boy who showed repeatedly the recurrent vomiting, intestinal pseudo obstruction and persistent muscle weakness over 1 year and 7 months There were no ophthalmoplegia. Barium clysis showed marked dilatation of colon. Cranial MRI in case 1 and CT in case 2 were unremarkable Muscle biopsies were performed in both cases and specimens were studied using routine histological and histochemical staining as well as using ultrastructural examination mtDNA analysis were performed in both cases Results Histological and enzym histochemical staining showed RRF and SDH positive fibers in both cases. Electron microscopic studies revealed mitochondrial proliferation with paracystalline inclusions in the muscle fibers with mild accumulation of lipid and glycogen. Genetic study revealed point mutation in mtDNA 3243A→G in case 1 and mtDNA3271T→C in case 2 Conclusion Mitochondrial cytopathy might be diagnosed upon the myopathological and genetic findings Different from MNGIE, Leigh disease and MELAS, the main clinical features were gastrointestinal symptoms, mild muscle weakness and no involvement of central nerve system in our patients, thus the mitochondrial entero myopathy, a new clinicopathological type of mitochondrial disorders, might be considered Since the muscle weakness was usually overlooked in patients with diarrhea, the mitochondrial cytopathy occurring should be considered with more attention as to elucidating the causes of children who have chronic gastrointestinal symptoms

Changes of enzyme histochemistry and ultrastructure in mitochondrial myopathy and encephalomyopathy / 中华神经科杂志

Objective To investigate the pathological features and clinical characteristics of primary mitochondrial myopathy and encephalomyopathy. Methods 11 cases of mitochondrial myopathy and encephalomyopathy were analyzed on clinical features, histochemical changes and ultrastructure observations of muscles. Results RRFs were found in all 11 cases by muscle staining of MGT under light microscope. 7 cases were only afflicated with muscle weakness, 4 cases also having impairment of central nervous system. The proportion of RRFs was 6.4% to 10.3%. We observed these cases under electronic microscope. In 9 cases,the ultrastructural alterations included subsarcolemmal accumulation of mitochondria,increases of the number,abnormal shape,disarrangement of cristae and paracrystaline inclusion bodies. In 2 cases the increase of mitochondrial number is only the alteration. Conclusions Typical RRF is valuable for diagnoses of mitochondrial myopathy and encephalomyopathy under light microscope. The accumulation of abnormal mitochondrials beneath sarcolemal,especially the paracrystaline inclusion bodies are significant in making a definite diagnosis of this disease under electronic microscope.