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P4.66 Childhood-onset progressive dystonia associated with m.14459G>A mutation in the mitochondrial DNA: a case report and review of the literature
678
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
1
Hirosaki University of Health and Welfare, Pathology and Medical Neuroscience, Hirosaki, Japan, 2 Hirosaki University School of Medicine, Pediatrics, Hirosaki, Japan, 3 National Aomori Hospital, Pediatrics, Namioka, Japan, 4 National Musashi Center for Neurology and Psychiatry, Tokyo, Japan, 5 National Center for Neurology and Psychiatry, Tokyo, Japan, 6 National Aomori Hospital, Pediatrics, Japan MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) is a maternally inherited multisystem mitochondrial disorder. The common cause of MELAS is a point mutation of mitochondrial DNA. The brain shows various profiles of infarctlike lesions, whose pathogenesis is still unclear, although the involvement of defective mitochondria in neurons and/or in vascular wall cells (mitochondrial angiopathy) is inferred. A 1-year-old boy showed apnea attacks. At age 5, 5.5 and 6, he developed 1st, 2nd and 3rd stroke-like episodes, respectively. His hemiplegia and difficulty of walking and feeding were deteriorated. There were elevations of lactic acid and pyruvic acid levels. Ragged red fibers were demonstrated by muscle biopsy. The mitochondrial DNA analysis revealed a point mutation (A3243G) of tRNALeu (UUR). Presenting hepatic dysfunction and cardiac failure, he died at age 10. The autopsy revealed marked brain atrophy (800 g) and hypertrophic cardiomyopathy (220 g). Microscopically there were many large and small, old and new infarct-like foci in almost all cerebral cortices with accentuation in the occipital lobes. The deep white matter was diffusely atrophied. Infarct-like lesions were also present in the striatum and thalamus. Pseudocalcium deposition was seen in the globus pallidus.In the cerebellum patchy foci of loss of Purkinje cells and granule cells were seen. In the spinal cord degeneration of the posterior and lateral columns was observed. Electron microscopy revealed degeneration of heart muscle cells, choroid plexus epithelial cells, and medial muscle cells and endothelial cells of small vessels with increased accumulation of abnormal mitochondria. The above observations support the hypothesis that energy deficiency due to mitochondrial dysfunction may be responsible for the selective involvement of the most energy requiring tissues such as brain and muscles. doi:10.1016/j.nmd.2010.07.259
P4.64 Clinical experience with L-arginine treatment in MELAS syndrome A. Ishii 1, A. Shioya 1, A. Hosaka 1, N. Ohkoshi 2, K. Nakamagoe 1, A. Tamaoka 1 1 University of Tsukuba, Neurology, Tsukuba, Japan, 2 Tsukuba University of Technology, Neurology, Tsukuba, Japan
Background: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare mitochondrial disorder with a wide range of multisystemic symptoms. Prevention of stroke-like episode is one of the most important strategies for MELAS treatment. It has reported that L-arginine therapy decreased severity of stroke-like symptoms in MELAS. Here we report the clinical experience with intravenous administration of Larginine to the patients associated with acute stroke-like episode. Patients: We administrated intravenous L-arginine therapy to 4 MELAS patients. All were Japanese and diagnosed with MELAS according to clinical findings, ragged-red fibers in muscle biopsy, and A3243G mutation in the mitochondrial tRNALcu(UUR) gene in peripheral lymphocytes. Ages of onset were 9, 13, 46, and 50-year-
old. Two adult-onset patients had deafness and impaired glucose tolerance. Results: Patient 1 was admitted our hospital due to headache, hemianopsia, and convulsion. His first attack was at 9-year-old and he was diagnosed MELAS at 13-year-old. Since 13-year-old he had six stroke-like episodes and took L-arginine therapy. He has no side effects and L-arginine therapy makes his symptoms recover. Patient 2 had admitted our hospital 12 times because of stroke-like episodes and took L-arginine therapy. Although he has mild hemianopsia and fatigue, he is a student in University. Patient 3 was admitted our hospital because of headache and dysarthria. After L-arginine therapy, she developed hypercloremic acidosis. Patient 4 was admitted our hospital because of convulsion and left hand apraxia. After L-arginine therapy, he developed hypercloremic acidosis. Conclusion: Although administration of L-arginine was decreased severity of stroke-like episode in young-onset patients, hyperchloremic metabolic acidosis was occurred in adult-onset patients. The administration of L-arginine to the adult-onset MELAS patients requires careful attention. doi:10.1016/j.nmd.2010.07.260
P4.65 Clinical, pathological and radiological survey of two patients in a Chinese family with Leigh syndrome J. Hu, H.R. Shen The Third Hospital of Hebei Medical University, Neuromuscular Department, Shijiazhuang, Hebei, China We studied the characteristics of clinical, pathological and radiological survey of two patients in a Chinese family with Leigh syndrome. The common clinical characteristic was motor retardation. Two patients had elevated lactate in the blood. One patient had subacute loss of vision in two eyes. The muscle biopsy of two patients showed cytocrome-c oxidase deficiency. Brain magnetic resonance imaging revealed abnormal symmetrical lesions in the Semi-oval center and cerebellar dentate nucleus and revealed increased signal in diffusion-weighted imaging in the parietal white matter, bilaterally and symmetrically not respecting vascular territory or boundaries. Brain magnetic resonance spectroscopy revealed abnormal lactate peak in two patients. In the radiological survey studied, we found that the range of abnormal signal in brain magnetic resonance imaging and diffusion-weighted imaging, when lactate peaks decreased in brain magnetic resonance spectroscopy during improvement of the disease course. The study showed the changes of neuroimaging maybe associated with the course and the state of Leigh syndrome. doi:10.1016/j.nmd.2010.07.261
P4.66 Childhood-onset progressive dystonia associated with m.14459G>A mutation in the mitochondrial DNA: a case report and review of the literature A. Koide 1, H. Ozawa 2, M. Kubota 3, Y. Goto 4 1
Tokyo Metropolitan Children’s Medical Center, Division of Neurology, Tokyo, Japan, 2 Shimada Center for Rehabilitation and Neurodevelopmental Intervention, Department of Regional Medical Support, Tokyo, Japan, 3 National Center for Child Development and Healt, Division of Neurology, Tokyo, Japan, 4 National Institute of Neuroscience, NCNP, Department of Mental Retardation and Birth Defect Research, Tokyo, Japan
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
We report the clinical, radiological, and molecular findings in a boy presenting with progressive generalized dystonia in whom we have identified a mutation (m.14459G>A) in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene. The patient is a 7year-old boy with no family history of optic neuropathy or dystonia. He presented at age 3 with focal dystonia in the upper limb and progressed over 4 years to exhibit dystonia in bilateral upper and lower limbs. He also has dysarthria and walking difficulties. Ophthalmologic examination showed no apparent finding suggestive of optic neuropathy. Magnetic resonance imaging (MRI) of the brain showed high signal-intensity lesions in the putamen, caudate nucleus and midbrain on T2-weighted images. Mitochondrial DNA analysis revealed a G-to-A transition at nucleotide position 14,459 leading to alanine-to-valine amino acid substitution at position 72 of the ND6 subunit of complex I. The m.14459G>A mutation has been rarely reported in the patients presenting with Leber’s hereditary optic neuropathy (LHON), LHON with dystonia, or Leigh’s syndrome. We treated our patient with coenzyme-Q10, L-carnitine, vitamins, and sodium succinate. The authors review the clinical manifestations, radiological findings, and medical management regarding mitochondrial diseases caused by m.14459G>A mutation. doi:10.1016/j.nmd.2010.07.262
P4.67 A clinical and histopathological study of patients with mitochondrial abnormalities H. Karasoy, O.E. Ozbay, A.N. Yuceyar Ege University Medical School Hospital, Neurology, Bornova-Izmir, Turkey Mitochondrial diseases are clinically a heterogenous group of disorders with widely varying clinical features that can present from birth to old age. Achieving accurate diagnosis can be difficult and requires synthesis of clinical, biochemical, enzymatic, histopathologic and molecular data. Muscle biopsy provides the best information to confirm a mithocondrial disease. We retrospectively reviewed clinical and laboratory features in 94 patients with mitochondrial pathology (more than 1% ragged-red, ragged-blue and cox-negative fibers) on muscle biopsy, seen during the last 10 years period. Clinical and other pathological findings were consistent with nonmitochondrial diseases in 28 patients with the final diagnosis of muscular dystrophy in 15 patients, myositis in 3 patients, hereditary IBM in 2 patients, and it was related to ageing in 8 patients. The remaining 66 patients were considered as primary mitochondrial diseases based on clinical and pathological criteria. We analyzed clinical features of these 66 patients. The most common clinical syndrome was progressive external ophtalmoplegia (PEO) with or without other findings, in 55 (83.3%) patients. Twenty-two patients (33.3%) had only PEO, 34 patients (51.5%) presented with proximal muscle weakness with or without other systemic findings. Two patients had both proximal and distal weakness along with PEO. Four patients had clinical features of Kearns Sayre syndrome, 2 patients had PEO plus Parkinson’s disease, 1 patient had MNGIE, 1 patient had sideroblastic anemia and mitochondrial myopathy. Mitochondrial abnormalities occur in many nonmitochondrial and mitochondrial diseases. The accurate diagnosis of mitochondrial diseases relies on a multidisciplinary approach, and muscle biopsy is often useful in the differential diagnosis of a wide range of neuromuscular presentations. doi:10.1016/j.nmd.2010.07.263
679
NEW DISEASES; ORAL PRESENTATIONS O.19 Inactivation of glycogen synthesis priming due to a missense mutation in glycogenin-1 – A new disease mechanism A.-R. Moslemi 1, C. Lindberg 2, J. Nilsson 3, H. Tajsharghi 1, B. Andersson 4, A. Oldfors 1 Gothenburg University, Pathology, Gothenburg, Sweden, 2 Gothenburg University, Neurology, Gothenburg, Sweden, 3 Gothenburg University, Gothenburg, Sweden, 4 Gothenburg University, Cardiology, Gothenburg, Sweden 1
Glycogen, the storage form of glucose in many cell types, is essential for energy supply and glucose homeostasis. Glycogenin is a glycosyl transferase that catalyzes the formation of a short glucose polymer of approximately ten glucose residues from UDP-glucose in an auto-glucosylation reaction. This reaction is followed by elongation and branching of the polymer, catalyzed by glycogen synthase and branching enzyme, to form glycogen. There are two glycogenin isoforms in humans. Glycogenin-1, encoded by GYG1 is the muscle isoform. It is also expressed in other tissues, but only to a minor degree in liver. Glycogenin-2, which is the liver isoform, is encoded by GYG2. It is expressed in cardiac muscle and other tissues to some extent, but not in skeletal muscle. We report a 27-year-old man experienced dizziness and palpitations shortly after exercising, and emergency medical services were called. On arrival of the ambulance the patient was noted to be in ventricular fibrillation, which was converted to sinus rhythm by cardiac defibrillation. The following investigation showed that he had cardiomyopathy and muscle weakness associated with profound depletion of glycogen in skeletal muscle and abnormal storage in the heart. Sequencing of the glycogenin-1 gene GYG1 revealed a nonsense mutation in one allele and a missense mutation, Thr83Met, in the other. Only the missense mutation was expressed in skeletal and cardiac muscle tissue, and caused inactivation of the normal autoglucosylation of glycogenin-1. This is a new metabolic disorder, which demonstrates the importance of glycogenin-1 for the priming of glycogen synthesis in human muscle. Glycogenin-1 deficiency should therefore be considered in patients with cardiac arrhythmia and/or muscle weakness. Endomyocardial and skeletal muscle biopsy may provide the clue to correct diagnosis. doi:10.1016/j.nmd.2010.07.264
O.20 Human disease caused by loss of fast IIa myosin heavy chain due to MYH2 mutations H.T. Tajsharghi 1, D.H.J. Hilton-Jones 2, O.R. Raheem 3, A.M.S. Saukkonen 4, A.O. Oldfors 1, B.U. Udd 5 1 Institute of Biomedicine, University of Gothenburg, Pathology, Gothenburg, Sweden, 2 John Racliffe Hospital, Neurology, Oxford, United Kingdom, 3 Tampere University and Hospital, Neuromuscular Center, Tampere, Finland, 4 Central Hospital of Northern Karelia, Neurology, Joensuu, Finland, 5 Vasa Central Hospital, Neurology, Vasa, Finland
Myosin is one of the most abundant proteins in the body and is indispensable for body movement and heart contractility. Striated muscle myosin heavy chain (MyHC) is a molecular motor protein that converts chemical energy into mechanical force. Three major myosin heavy chain (MyHC) isoforms are present in adult human
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
1
Hirosaki University of Health and Welfare, Pathology and Medical Neuroscience, Hirosaki, Japan, 2 Hirosaki University School of Medicine, Pediatrics, Hirosaki, Japan, 3 National Aomori Hospital, Pediatrics, Namioka, Japan, 4 National Musashi Center for Neurology and Psychiatry, Tokyo, Japan, 5 National Center for Neurology and Psychiatry, Tokyo, Japan, 6 National Aomori Hospital, Pediatrics, Japan MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) is a maternally inherited multisystem mitochondrial disorder. The common cause of MELAS is a point mutation of mitochondrial DNA. The brain shows various profiles of infarctlike lesions, whose pathogenesis is still unclear, although the involvement of defective mitochondria in neurons and/or in vascular wall cells (mitochondrial angiopathy) is inferred. A 1-year-old boy showed apnea attacks. At age 5, 5.5 and 6, he developed 1st, 2nd and 3rd stroke-like episodes, respectively. His hemiplegia and difficulty of walking and feeding were deteriorated. There were elevations of lactic acid and pyruvic acid levels. Ragged red fibers were demonstrated by muscle biopsy. The mitochondrial DNA analysis revealed a point mutation (A3243G) of tRNALeu (UUR). Presenting hepatic dysfunction and cardiac failure, he died at age 10. The autopsy revealed marked brain atrophy (800 g) and hypertrophic cardiomyopathy (220 g). Microscopically there were many large and small, old and new infarct-like foci in almost all cerebral cortices with accentuation in the occipital lobes. The deep white matter was diffusely atrophied. Infarct-like lesions were also present in the striatum and thalamus. Pseudocalcium deposition was seen in the globus pallidus.In the cerebellum patchy foci of loss of Purkinje cells and granule cells were seen. In the spinal cord degeneration of the posterior and lateral columns was observed. Electron microscopy revealed degeneration of heart muscle cells, choroid plexus epithelial cells, and medial muscle cells and endothelial cells of small vessels with increased accumulation of abnormal mitochondria. The above observations support the hypothesis that energy deficiency due to mitochondrial dysfunction may be responsible for the selective involvement of the most energy requiring tissues such as brain and muscles. doi:10.1016/j.nmd.2010.07.259
P4.64 Clinical experience with L-arginine treatment in MELAS syndrome A. Ishii 1, A. Shioya 1, A. Hosaka 1, N. Ohkoshi 2, K. Nakamagoe 1, A. Tamaoka 1 1 University of Tsukuba, Neurology, Tsukuba, Japan, 2 Tsukuba University of Technology, Neurology, Tsukuba, Japan
Background: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare mitochondrial disorder with a wide range of multisystemic symptoms. Prevention of stroke-like episode is one of the most important strategies for MELAS treatment. It has reported that L-arginine therapy decreased severity of stroke-like symptoms in MELAS. Here we report the clinical experience with intravenous administration of Larginine to the patients associated with acute stroke-like episode. Patients: We administrated intravenous L-arginine therapy to 4 MELAS patients. All were Japanese and diagnosed with MELAS according to clinical findings, ragged-red fibers in muscle biopsy, and A3243G mutation in the mitochondrial tRNALcu(UUR) gene in peripheral lymphocytes. Ages of onset were 9, 13, 46, and 50-year-
old. Two adult-onset patients had deafness and impaired glucose tolerance. Results: Patient 1 was admitted our hospital due to headache, hemianopsia, and convulsion. His first attack was at 9-year-old and he was diagnosed MELAS at 13-year-old. Since 13-year-old he had six stroke-like episodes and took L-arginine therapy. He has no side effects and L-arginine therapy makes his symptoms recover. Patient 2 had admitted our hospital 12 times because of stroke-like episodes and took L-arginine therapy. Although he has mild hemianopsia and fatigue, he is a student in University. Patient 3 was admitted our hospital because of headache and dysarthria. After L-arginine therapy, she developed hypercloremic acidosis. Patient 4 was admitted our hospital because of convulsion and left hand apraxia. After L-arginine therapy, he developed hypercloremic acidosis. Conclusion: Although administration of L-arginine was decreased severity of stroke-like episode in young-onset patients, hyperchloremic metabolic acidosis was occurred in adult-onset patients. The administration of L-arginine to the adult-onset MELAS patients requires careful attention. doi:10.1016/j.nmd.2010.07.260
P4.65 Clinical, pathological and radiological survey of two patients in a Chinese family with Leigh syndrome J. Hu, H.R. Shen The Third Hospital of Hebei Medical University, Neuromuscular Department, Shijiazhuang, Hebei, China We studied the characteristics of clinical, pathological and radiological survey of two patients in a Chinese family with Leigh syndrome. The common clinical characteristic was motor retardation. Two patients had elevated lactate in the blood. One patient had subacute loss of vision in two eyes. The muscle biopsy of two patients showed cytocrome-c oxidase deficiency. Brain magnetic resonance imaging revealed abnormal symmetrical lesions in the Semi-oval center and cerebellar dentate nucleus and revealed increased signal in diffusion-weighted imaging in the parietal white matter, bilaterally and symmetrically not respecting vascular territory or boundaries. Brain magnetic resonance spectroscopy revealed abnormal lactate peak in two patients. In the radiological survey studied, we found that the range of abnormal signal in brain magnetic resonance imaging and diffusion-weighted imaging, when lactate peaks decreased in brain magnetic resonance spectroscopy during improvement of the disease course. The study showed the changes of neuroimaging maybe associated with the course and the state of Leigh syndrome. doi:10.1016/j.nmd.2010.07.261
P4.66 Childhood-onset progressive dystonia associated with m.14459G>A mutation in the mitochondrial DNA: a case report and review of the literature A. Koide 1, H. Ozawa 2, M. Kubota 3, Y. Goto 4 1
Tokyo Metropolitan Children’s Medical Center, Division of Neurology, Tokyo, Japan, 2 Shimada Center for Rehabilitation and Neurodevelopmental Intervention, Department of Regional Medical Support, Tokyo, Japan, 3 National Center for Child Development and Healt, Division of Neurology, Tokyo, Japan, 4 National Institute of Neuroscience, NCNP, Department of Mental Retardation and Birth Defect Research, Tokyo, Japan
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
We report the clinical, radiological, and molecular findings in a boy presenting with progressive generalized dystonia in whom we have identified a mutation (m.14459G>A) in the mitochondrial NADH dehydrogenase subunit 6 (ND6) gene. The patient is a 7year-old boy with no family history of optic neuropathy or dystonia. He presented at age 3 with focal dystonia in the upper limb and progressed over 4 years to exhibit dystonia in bilateral upper and lower limbs. He also has dysarthria and walking difficulties. Ophthalmologic examination showed no apparent finding suggestive of optic neuropathy. Magnetic resonance imaging (MRI) of the brain showed high signal-intensity lesions in the putamen, caudate nucleus and midbrain on T2-weighted images. Mitochondrial DNA analysis revealed a G-to-A transition at nucleotide position 14,459 leading to alanine-to-valine amino acid substitution at position 72 of the ND6 subunit of complex I. The m.14459G>A mutation has been rarely reported in the patients presenting with Leber’s hereditary optic neuropathy (LHON), LHON with dystonia, or Leigh’s syndrome. We treated our patient with coenzyme-Q10, L-carnitine, vitamins, and sodium succinate. The authors review the clinical manifestations, radiological findings, and medical management regarding mitochondrial diseases caused by m.14459G>A mutation. doi:10.1016/j.nmd.2010.07.262
P4.67 A clinical and histopathological study of patients with mitochondrial abnormalities H. Karasoy, O.E. Ozbay, A.N. Yuceyar Ege University Medical School Hospital, Neurology, Bornova-Izmir, Turkey Mitochondrial diseases are clinically a heterogenous group of disorders with widely varying clinical features that can present from birth to old age. Achieving accurate diagnosis can be difficult and requires synthesis of clinical, biochemical, enzymatic, histopathologic and molecular data. Muscle biopsy provides the best information to confirm a mithocondrial disease. We retrospectively reviewed clinical and laboratory features in 94 patients with mitochondrial pathology (more than 1% ragged-red, ragged-blue and cox-negative fibers) on muscle biopsy, seen during the last 10 years period. Clinical and other pathological findings were consistent with nonmitochondrial diseases in 28 patients with the final diagnosis of muscular dystrophy in 15 patients, myositis in 3 patients, hereditary IBM in 2 patients, and it was related to ageing in 8 patients. The remaining 66 patients were considered as primary mitochondrial diseases based on clinical and pathological criteria. We analyzed clinical features of these 66 patients. The most common clinical syndrome was progressive external ophtalmoplegia (PEO) with or without other findings, in 55 (83.3%) patients. Twenty-two patients (33.3%) had only PEO, 34 patients (51.5%) presented with proximal muscle weakness with or without other systemic findings. Two patients had both proximal and distal weakness along with PEO. Four patients had clinical features of Kearns Sayre syndrome, 2 patients had PEO plus Parkinson’s disease, 1 patient had MNGIE, 1 patient had sideroblastic anemia and mitochondrial myopathy. Mitochondrial abnormalities occur in many nonmitochondrial and mitochondrial diseases. The accurate diagnosis of mitochondrial diseases relies on a multidisciplinary approach, and muscle biopsy is often useful in the differential diagnosis of a wide range of neuromuscular presentations. doi:10.1016/j.nmd.2010.07.263
679
NEW DISEASES; ORAL PRESENTATIONS O.19 Inactivation of glycogen synthesis priming due to a missense mutation in glycogenin-1 – A new disease mechanism A.-R. Moslemi 1, C. Lindberg 2, J. Nilsson 3, H. Tajsharghi 1, B. Andersson 4, A. Oldfors 1 Gothenburg University, Pathology, Gothenburg, Sweden, 2 Gothenburg University, Neurology, Gothenburg, Sweden, 3 Gothenburg University, Gothenburg, Sweden, 4 Gothenburg University, Cardiology, Gothenburg, Sweden 1
Glycogen, the storage form of glucose in many cell types, is essential for energy supply and glucose homeostasis. Glycogenin is a glycosyl transferase that catalyzes the formation of a short glucose polymer of approximately ten glucose residues from UDP-glucose in an auto-glucosylation reaction. This reaction is followed by elongation and branching of the polymer, catalyzed by glycogen synthase and branching enzyme, to form glycogen. There are two glycogenin isoforms in humans. Glycogenin-1, encoded by GYG1 is the muscle isoform. It is also expressed in other tissues, but only to a minor degree in liver. Glycogenin-2, which is the liver isoform, is encoded by GYG2. It is expressed in cardiac muscle and other tissues to some extent, but not in skeletal muscle. We report a 27-year-old man experienced dizziness and palpitations shortly after exercising, and emergency medical services were called. On arrival of the ambulance the patient was noted to be in ventricular fibrillation, which was converted to sinus rhythm by cardiac defibrillation. The following investigation showed that he had cardiomyopathy and muscle weakness associated with profound depletion of glycogen in skeletal muscle and abnormal storage in the heart. Sequencing of the glycogenin-1 gene GYG1 revealed a nonsense mutation in one allele and a missense mutation, Thr83Met, in the other. Only the missense mutation was expressed in skeletal and cardiac muscle tissue, and caused inactivation of the normal autoglucosylation of glycogenin-1. This is a new metabolic disorder, which demonstrates the importance of glycogenin-1 for the priming of glycogen synthesis in human muscle. Glycogenin-1 deficiency should therefore be considered in patients with cardiac arrhythmia and/or muscle weakness. Endomyocardial and skeletal muscle biopsy may provide the clue to correct diagnosis. doi:10.1016/j.nmd.2010.07.264
O.20 Human disease caused by loss of fast IIa myosin heavy chain due to MYH2 mutations H.T. Tajsharghi 1, D.H.J. Hilton-Jones 2, O.R. Raheem 3, A.M.S. Saukkonen 4, A.O. Oldfors 1, B.U. Udd 5 1 Institute of Biomedicine, University of Gothenburg, Pathology, Gothenburg, Sweden, 2 John Racliffe Hospital, Neurology, Oxford, United Kingdom, 3 Tampere University and Hospital, Neuromuscular Center, Tampere, Finland, 4 Central Hospital of Northern Karelia, Neurology, Joensuu, Finland, 5 Vasa Central Hospital, Neurology, Vasa, Finland
Myosin is one of the most abundant proteins in the body and is indispensable for body movement and heart contractility. Striated muscle myosin heavy chain (MyHC) is a molecular motor protein that converts chemical energy into mechanical force. Three major myosin heavy chain (MyHC) isoforms are present in adult human