Duchenne muscular dystrophy dmd is a severe type of muscular dystrophy. All muscular dystrophies are characterized by ongoing degeneration and regeneration of muscle fibers. Facts about rare muscular dystrophies muscular dystrophy. Although guidelines are available for various aspects of dmd, comprehensive. Cardiac involvement occurs as a degenerative process with fibrosis and fatty replacement of the myocardium. Progressive muscular dystrophies causing progressive weakness. They include disorders such as duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, and limb girdle muscular dystrophy.
Muscular dystrophies are progressive, generalized diseases of muscle, most often caused by defective or specifically absent glycoproteins e. Some forms of md are seen in infancy or childhood, while others may not appear until middle age or later. Duchennetype muscular dystrophy also known as meryons disease is the. There has been rapid growth and change in our understanding of these disorders in recent years, and advances in basic science are being translated into increasing numbers of clinical trials. Since pseudohypertrophic muscular paralysis was first described by duchenne in 1868,2 researchers have greatly expanded the concept of dystrophies and their continuum of severity. Review diagnosis and management of duchenne muscular. In the most common form, duchenne muscular dystrophy, a few personalised therapies. Explain the inheritance pattern of duchenne muscular dystrophy and congenital. Duchenne muscular dystrophy is a genetically determined xlinked disease and the most common, progressive pediatric muscle disorder. They can be subdivided into several groups, including congenital forms, in accordance with the distribution of predominant muscle weakness. Arrhythmias in the muscular dystrophies heart rhythm. Muscular dystrophy is a group of inherited diseases that damage and weaken your muscles over time.
Muscle weakness usually becomes apparent between the ages of 5. The absence of this protein can cause problems with walking, swallowing, and muscle coordination. The muscular dystrophies comprise a heterogeneous group of genetic disorders that produce progressive skeletal muscle weakness and wasting. Consequently, the relative fitness in facioscapulohumeral progressive muscular dystrophy is 180.
In 1987, the protein associated with this gene was identified and named dystrophin. For decades, research has been conducted to find an effective. There are many different kinds of muscular dystrophy. Pdf progressive muscular dystrophies in children researchgate. 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. Congenital, distal, emerydreifuss and oculopharyngeal. The muscular dystrophies are an inherited group of progressive myopathic disorders resulting from defects in a number of genes required for normal muscle function. Les dystrophies musculaires progressives dmp dr sifl. Becker muscular dystrophy bmd is an inherited condition that causes progressive weakness and wasting of the skeletal and cardiac heart muscles. Duchenne muscular dystrophy dmd is a severe, progressive disease that affects 1 in 36006000 live male births. 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. Muscular dystrophies are a group of unrelated diseases, each transmitted by a different genetic trait and each differing in its clinical course and expression. The disorder shows a wide range of clinical symptoms, from mild myopathy to more severe cases with features of progressive muscular dystrophy although most.
It is a serious condition with progressive muscle wasting and weakness which. Muscular dystrophies are primary diseases of muscle due to mutations in more than 40 genes, which result in dystrophic changes on muscle biopsy. The main forms of muscular dystrophy may affect up to 1 in every. With advances of molecular genetics, the pathogenesis of some of these conditions has become understood. The patterns of inheritance, age of onset, patterns of muscular involvement and prognoses differ according to type. Muscular dystrophies symptoms, diagnosis and treatment. In early stages the muscle biopsy may just reveal a myopathic picture without clear dystrophic features, but the clinical context and morphology are able. Normalsibs ofthe patients whowere in the same age category totalled 16 andhad36 children, anaverage of225. Muscular dystrophies are commonly due to mutations involving muscular genes e. Duchenne muscular dystrophywas originally described by. The muscular dystrophies are a group of inherited diseases affecting skeletal muscle that also affect cardiac muscle. Though duchenne muscular dystrophy dmd is by far the most frequent and one of the most severe forms of the progressive muscular dystrophies, myogenic.
Problems with musclecontrolling nerves, or motor nerves, originating in the spinal cord and reaching out to all the muscles, can cause weakness that looks like a. Becker muscular dystrophy genetic and rare diseases. The muscular dystrophies md are a group of more than 30 genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Combined with bioengineering approaches for treatment of. A recent metaanalysis of worldwide prevalence of muscular dystrophies suggests prevalences of dmd and bmd as 0. Duchenne muscular dystrophy progressive skeletal muscle degeneration onset age 35. Though duchenne muscular dystrophy dmd is by far the most frequent and one of the most severe forms of the progressive muscular dystrophies, myogenic disorders characterized by progressive muscle wasting and weakness correspond in fact to a heterogeneous group of genetic disorders, grouped and designated under the term muscular dystrophies, that can occur at any age. Muscular dystrophies are a group of progressive diseases that affect the musculoskeletal system. Muscular dystrophies are a group of heritable muscle. This damage and weakness is due to the lack of a protein. Geneticepidemiological studies in progressive muscular. Symptoms of the most common variety begin in childhood, mostly in boys. After completing this article, readers should be able to. In several forms of md, cardiac dysfunction occurs and cardiac disease may even be the predominant manifestation of the.
The symptom of duchenne muscular dystrophy is a rare progressive disease which eventually affects all voluntary muscles and involves the heart and breathing. Geneticepidemiological studies in progressive musculardystrophy total of45 children, anaverage 1 80. The muscular dystrophies postgraduate medical journal. The different types can vary in whom they affect, which muscles they affect, and what the. Progressive muscular dystrophies knowledge for medical. Electrophysiologists are asked to participate in the care of muscular dystrophy patients because of the risk of atrial arrhythmias, conduction disease, bradycardia. Muscular dystrophies are heterogeneous genetic disorders that share progressive muscle wasting. Some are severe diseases at birth that lead to early death. The one program we did that seemed to work well was a walking program, where we put pedometers on people and asked them to walk 25 percent more over time than they did initially. Request pdf progressive muscular dystrophies infancy or childhoodonset muscular dystrophies may be associated with profound loss of muscle function, affecting ambulation, posture, cardiac.
Shamanthakamani narendran m u s c u l a r d y s t r o p h y m. Muscular dystrophy md connotes a heterogeneous group of inherited disorders characterized by progressive wasting and weakness of the skeletal muscles. In muscular dystrophy, abnormal genes mutations interfere with the production of proteins needed to form healthy muscle. This damage and weakness is due to the lack of a protein called dystrophin, which is necessary for normal muscle function. In the s, descriptions of boys who grew progressively weaker, lost the ability to walk, and died at an early age became more prominent musculaores medical journals.
Cardiac involvement in patients with muscular dystrophies. Muscular dystrophies mds consist of several genetic diseases that are caused by a variety of mutations in structural proteins, and that result in progressive degeneration and weakness due to muscle damage, in. Gastrointestinal manifestations of the muscular dystrophies. Muscular dystrophy md is a group of more than 30 inherited diseases. 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. Muscular dystrophy symptoms and causes mayo clinic. Associate professor, division of neurology, department of pediatrics, university of british columbia. The histopathological features of muscular dystrophies. Gradually, the muscles become weak enough that people experi ence the symptoms of limbgirdle muscular dystrophy. These mutations impact the function of proteins responsible for giving the muscle structural. Muscular dystrophies are a group of heritable muscle diseases that weaken the muscles of the body.
Clinically, muscular dystrophies are characterized by progressive muscle weakness affecting skel. Progressive muscular dystrophy an overview sciencedirect topics. 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. Pelvic girdle weakness difficulty arisingclimbing stairs. In the late 1980s, major advances in molecular genetics led to the discovery of the dystrophin gene and its. Dd, emerydreifuss muscular dystrophy edmd and oculopharyngeal muscular dystrophy opmd are among the rarer forms of muscular dystrophy.
Muscular dystrophy information page national institute. Duchenne muscular dystrophy dmd is a severe, progressive disease that a. The muscular dystrophies are progressive disorders affecting children and adults chelly and desguerre, 20. 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. In 1986, mdasupported researchers identified the gene that, when flawed a problem known as a mutation causes dmd.
Duchenne muscular dystrophy and becker muscular dystrophy bmd are xlinked recessive diseases, whereas limbgirdle muscular dystrophy may be either autosomal dominant or recessive. Muscular dystrophy is a group of diseases that cause progressive weakness and loss of muscle mass. Muscular dystrophy md is a group of muscle diseases that results in increasing weakening. Although guidelines are available for various aspects of dmd, comprehensive clinical care recommendations do not. Les muscles innerves par les nerfs craniens sont respectes.
Muscular dystrophies constitute a clinically and genetically heterogeneous group of skeletal musclewasting diseases. The muscular dystrophies are progressive, heredi tary diseases ge nerally thought of as involving only skeletal muscle, but gastrointestinal symptoms often accompany these disorders, and they may be found in a large proportion of patients table 1. It is now well known that all forms of muscular dystrophies are genetic. Muscular dystrophy refers a group of disorders that involve a progressive loss of muscle mass and consequent loss of strength.
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