Recent findings more than 30 genes have been associated with these diseases, most of which have only been recognized in the past decade. Disorders of muscle can be simplified into the following categories. Muscular dystrophies and other muscle diseases basicmedical key. There are several types of muscular dystrophy and each has differing severities and progressions. Pathogenesis of muscular dystrophies jama neurology jama. Neoepitope peptides as biomarkers of disease progression for muscular dystrophies and other myopathies article pdf available august 2016 with 92 reads how we measure reads. Other inheritable myopathies cause episodes of muscle weakness or stiffness that are milder and more localized and temporary in nature. The panel covers all types of muscular dystrophies, myopathies, and other neuromuscular disorders encompassing more than 300 diseases to date. Patients with these conditions share characteristics such as early onset of weakness and severe hypotonia. The first muscles to be affected by weakness are those of the face, neck, hands, forearms, and feet. These mutations impact the function of proteins responsible. Unlike the other muscular dystrophies, the muscle weakness is accompanied by myotonia delayed relaxation of muscles after contraction and by various other nonmuscular symptoms. Mitochondrial myopathies muscular dystrophies myotonias acquired druginduced myopathies endocrine myopathies.
Neoepitope peptides as biomarkers of disease progression. Other organs such as the brain, eyes, and skin may be involved. Sep 27, 2016 the panel covers all types of muscular dystrophies, myopathies, and other neuromuscular disorders encompassing more than 300 diseases to date. Increasing availability of dna analysis has been important in decreasing delay in.
The 6minute walk test and other endpoints in duchenne muscular dystrophy. This article summarizes the clinical and genetic aspects of these disorders. The different types can vary in whom they affect, which muscles they affect, and what the symptoms are. Disease bioinformatics muscular dystrophies and myopathies is a group of conditions that weaken muscles and hinder movement. Skeletal muscle diseases, or myopathies, are disorders with structural changes or functional impairment of muscle.
Congenital muscular dystrophies cmds are clinically and genetically. Three major theories have been proposed to explain the pathogenesis of muscular dystrophies. The disease affects the muscles with definite fiber degeneration but without evidence of morphologic aberrations. Muscular dystrophies and other inherited myopathies request pdf. Congenital muscular dystrophies cmds are overall clinically and genetically heterogeneous neuromuscular disorders with onset at birth or in infancy and in which the muscle biopsy is compatible with the presence of a dystrophic myopathy. When other cranial nerve muscles are weak, causing ptosis or extraocular muscle weakness, the most important disorders to consider include neuromuscular junction disorders, oculopharyngeal muscular dystrophy, mitochondrial myopathies, or some of the congenital myopathies table 462e1. The inflammatory process leads to destruction of muscle tissue, and is. The muscular dystrophies are inherited myogenic disorders characterised by progressive muscle wasting and weakness of variable distribution and severity. Unfortunately, gene replacement strategies are not indicated for treating dominant diseases, where reduction or elimination of an abnormal allele would be needed, and as a result, gene therapies for dominant muscular dystrophies have lagged behind. Muscular dystrophy md is a group of more than 30 inherited diseases. Myopathies can be distinguished from other disorders of the motor unit, including the. Other symptoms of myopathy can include include muscle cramps, stiffness, and spasm.
Request pdf muscular dystrophies and other inherited myopathies it is certain that more inherited neuromuscular disorders of dogs and cats will be identified as the ability of practicing. Unlike muscular dystrophies, myopathies usually dont cause muscles to. Types of muscular dystrophy and neuromuscular diseases. An approach to myopathy for the primary care clinician american. The pattern of weakness, tempo of evolution, and mode of inheritance vary among different dystrophies. A myopathy is a muscle disease, and inflammation is a response to cell damage. Unfortunately, most of them have very similar clinical presentations and even with thorough clinical evaluation and muscle pathology, a correct diagnosis without genetic testing remains difficult. The inflammatory myopathies are a group of muscle diseases that involve inflammation of the muscles or associated tissues, such as the blood vessels that supply the muscles. Jul 22, 2016 overall 167 unrelated patients presenting nmd falling into categories of muscular dystrophies, congenital muscular dystrophies, congenital myopathies, distal myopathies, and other myopathies were tested by targeted ngs of 42 known nmd. Some types are also associated with problems in other organs.
Longitudinal natural history observations over 48 weeks from a multicenter study. Listed below are the 9 different types of muscular dystrophy. It summarizes the advances in molecular and cell biology, biochemistry, and other biological sciences, with an emphasis on their application to this group of muscle disorders and to their clinical implications. Despite advances in genetics, the importance of the clinical history and physical examination has increased rather than diminished. Muscular dystrophies and other inherited myopathies. From the department of neurology, college of physicians and surgeons, columbia university, and the neurological institute, columbiapresby terian. Duchenne muscular dystrophy dmd is highlighted as the most common and most rapidly progressive muscular dystrophy, with most patients losing the ability to walk by 12 years of age and requiring ventilatory support by 25 years of age. Knowledge of diseasespecific complications, implementation of anticipatory care, and medical advances. The muscular dystrophies are a group of inherited disorders characterised by progressive muscle wasting and weakness.
Modern molecular genetic techniques have made it possible to clarify the genetic mutations responsible for most muscular dystrophies. The cumulative evidence suggests that an abnormal muscle surface membrane is the most likely, but this has not been proven. Us20160008320a1 us14798,877 us201514798877a us2016008320a1 us 20160008320 a1 us20160008320 a1 us 20160008320a1 us 201514798877 a us201514798877 a us 201514798877a us 2016008320 a1 us2016008320 a1 us 2016008320a1 authority us united states prior art keywords muscle mdx statin simvastatin mice prior art date 20140714 legal status the legal status is an. A pathognomonic pattern characteristic of inclusion body. The inherited myopathies and muscular dystrophies are a diverse group of muscle diseases. Congenital muscular dystrophy and congenital myopathy. They can be subdivided into several groups, including congenital forms, in accordance with the distribution of predominant muscle weakness. Recent findings historically, diagnoses of congenital muscular dystrophy and congenital myopathy. For example, limb girdle muscular dystrophy is an umbrella name for a group of diseases which exhibits. The most well known of the muscular dystrophies is duchenne muscular dystrophy dmd, followed by becker muscular dystrophy bmd.
The histopathological features of muscular dystrophies. Their inheritance is either autosomal dominant lgmd1 or. In 1987, the protein associated with this gene was identified and named dystrophin. Muscular dystrophies and other genetic myopathies neurologic. A unifying feature of the dystrophies is the histological analysis of muscle samples which typically includes variations in fibre size, areas of muscle necrosis, and, ultimately, increased amounts of fat and connective tissue. Oct 10, 1998 the muscular dystrophies are a group of inherited disorders characterised by progressive muscle wasting and weakness.
Facts about rare muscular dystrophies muscular dystrophy. Weakness is mainly proximal and the muscular dystrophies alan e h emery seminar the muscular dystrophies are inherited myogenic disorders characterised by progressive muscle wasting and weakness of variable distribution and severity. Muscular dystrophies, polymyositis, and other myopathies. Adult and adolescent onset muscular dystrophies mds are a group of disorders that cause muscle disease myopathy characterized by progressive muscle weakness myasthenia and muscle degeneration atrophy due to mutations in one or more genes required for normal muscle function 21. Other recognized varieties of muscular dystrophies are classified into different groups according to their clinical or genetic similarities. Jul 11, 20 muscular dystrophies muscular dystrophy refers to a group of hereditary progressive diseases each with unique phenotypic and genetic features 16. Neoepitope peptides as biomarkers of disease progression for muscular dystrophies and other myopathies.
Findings historically, diagnoses of congenital muscular dystrophy and congenital myopathy have been made by clinical features and histopathology. In early stages the muscle biopsy may just reveal a myopathic picture without clear dystrophic features. From the department of neurology, college of physicians and surgeons, columbia university, and the neurological institute, columbiapresby terian medical center received for publication july 11, 1958. Recent findings historically, diagnoses of congenital muscular dystrophy and congenital myopathy have. Besides being an issue in the form of cachexia and sarcopenia, it is additionally important in a range of neuromuscular diseases, namely muscular dystrophies, congenital myopathies and myositis. Muscular dystrophies are a genetically and phenotypically heterogeneous group of progressive muscle diseases. These episodes often can be managed through medication, or by careful control of exercise and diet.
The disorders differ in which muscles are primarily affected, the degree of weakness, how fast they worsen, and when symptoms begin. Us20160008320a1 statins in the treatment of muscular. Myopathy is when the muscle fibers do not function properly. Home 20 icd9cm diagnosis codes diseases of the nervous system and sense organs 320389 disorders of the peripheral nervous system 350359 muscular dystrophies and other myopathies 359. Over 30 genes causing muscular dystrophy are known presently. These conditions can be differentiated from other diseases of the motor unit e.
The myopathies are neuromuscular disorders in which the primary symptom is muscle weakness due to dysfunction of muscle fiber. Neoepitope peptides as biomarkers of disease progression for. Mar 27, 2019 the myopathies are neuromuscular disorders in which the primary symptom is muscle weakness due to dysfunction of muscle fiber. Muscular dystrophies are a heterogeneous group of inherited disorders that share similar clinical features and dystrophic changes on muscle biopsy. Diagnosis depends largely on recognition of phenotype, muscle biopsy, and mutation analysis. Dec 16, 2019 muscular dystrophy md is a collective group of inherited noninflammatory but progressive muscle disorders without a central or peripheral nerve abnormality.
With advances of molecular genetics, the pathogenesis of some of these conditions has become understood. Myopathies are disorders with structural changes or functional impairment of muscle and can be differentiated from other diseases of the motor unit e. Facts about myopathies muscular dystrophy association. Myopathies can be inherited such as the muscular dystrophies or acquired such as common muscle cramps. Overall 167 unrelated patients presenting nmd falling into categories of muscular dystrophies, congenital muscular dystrophies, congenital myopathies, distal myopathies, and other myopathies were tested by targeted ngs of 42 known nmd.
Until the 1980s, little was known about the cause of any kind of muscular dystrophy. Muscular dystrophies discusses the pathogenesis and treatment prospects for muscular dystrophies. Muscular dystrophy md is a group of muscle diseases that results in increasing weakening and breakdown of skeletal muscles over time. Central core myopathy, fsh, limbgirdle muscular dystrophy type 1. Now that most of the genes responsible for these conditions have been identified, it is possible to accurately diagnose them and implement subtypespecific anticipatory care, as complications such as cardiac and respiratory muscle involvement vary. An improved understanding of their molecular bases has led to more accurate definitions of the clinical features associated with known subtypes. Pdf inherited myopathies and muscular dystrophies researchgate. Congenital muscular dystrophies and congenital myopathies. Diseases characterized by muscular weakness in early infancy typically obvious at birth and elevated ck in neonatal period normalizes by 610 wks. This meaning implies that the primary defect is within the muscle, as opposed to the nerves neuropathies or neurogenic disorders or elsewhere e.
These mutations impact the function of proteins responsible for giving the muscle structural. Clinically, muscular dystrophies are typically progressive, because the muscles ability to regenerate is eventually lost, leading to progressive weakness, often leading to use of a wheelchair, and eventually death. Rnai therapy for dominant muscular dystrophies and other. In performing manual muscle testing of the upper extremities, it is necessary to. The congenital muscular dystrophies cmd and myopathies cm are a diverse group of diseases that share features such as early onset of symptoms in the first year of life, genetic causes, and high risks for restrictive lung disease and orthopedic deformities. Each type differs in the muscles affected, the age of onset, and its rate of progression. Muscular dystrophies and other genetic myopathies oxford. In early stages the muscle biopsy may just reveal a myopathic picture without clear dystrophic features, but the clinical context and morphology are able. The inherited myopathies and muscular dystrophies are a diverse group of muscle diseases presenting with common complaints and physical signs. In 1986, mdasupported researchers identified the gene that, when flawed a problem known as a mutation causes dmd. Some types are named for the affected muscles, including the. Muscular dystrophies are primary diseases of muscle due to mutations in more than 40 genes, which result in dystrophic changes on muscle biopsy. Muscular dystrophies investigations bmj best practice.
The expansion of the spectrum of limb girdle muscular dystrophies lgmds in recent years means that neurologists need to be familiar with the clinical clues that can help with their diagnosis. Duchennes muscular dystrophy also called pseudo hypertrophic muscular dystrophy. Pathogenic or probably pathogenic sequence changes were identified in 79 patients 47. It is now well known that all forms of muscular dystrophies are genetic. In medicine, myopathy is a disease of the muscle in which the muscle fibers do not function properly. Other inheritable myopathies cause epi sodes of muscle weakness or stiffness that are milder and more localized and temporary in nature. Muscular dystrophy myopathy limbgirdle fshd myotonic dystrophy. Inherited myopathies and muscular dystrophies macpeds. Shamanthakamani narendran m u s c u l a r d y s t r o p h y m. Muscular dystrophies muscular dystrophy refers to a group of hereditary progressive diseases each with unique phenotypic and genetic features 16. A firstline diagnostic assay for limbgirdle muscular. Pdf the inherited myopathies and muscular dystrophies are a diverse group of muscle diseases.