Congenital myopathies metabolic myopathies mitochondrial myopathies muscular dystrophies myotonias. Patients may present with indolent myopathic features, exercise intolerance or recurrent rhabdomyolysis. Clinical approach to the diagnosis of congenital myopathies 2011 documento. Congenital myopathies are a group of genetic muscle disorders characterized clinically by hypotonia and weakness, usually from birth, and a static or slowly progressive clinical course. The first report of a congenital myopathy was in 1956, when a patient with central core disease ccd was described.
The group of congenital myopathies, sometimes also known as the structural myopathies, is, to some extent, more satisfying to the histopathologist because they are. Congenital myopathies are a group of genetic muscle disorders. Approach to the interpretation of muscle biopsy 17 located in the perimysium. Over the past decade there have been major advances in defining the genetic basis of the majority of congenital myopathy subtypes. Em is important, however, in the diagnosis of some congenital myopathies and mitochondrial disorders. An integrated diagnosis strategy for congenital myopathies. Congenital myopathy early onset nemaline myotubular centronuclear congenital fibretype disproportion. The muscle tissue can also be processed for biochemical analysis to determine a specific enzyme defect in the evaluation of a possible metabolic or mitochondrial myopathy. Congenital present at birth myopathies have a genetic basis, meaning they can be passed from parent to child. Congenital myopathies msd manual professional edition. Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by earlyonset.
Congenital myopathies account for one of the top neuromuscular disorders in the world today, comprising approximately 6 in 100,000 live births every year. Several clinical features are uncommon in congenital myopathies and if present, should alert the clinician to the presence of an alternative diagnosis. There can be significant clinical overlap between congenital myopathies and other neuromuscular disorders including the congenital muscular dystrophies cmd, congenital myotonic dystrophy, congenital myasthenic syndromes cms, metabolic myopathies including pompe disease. Genes that cause congenital myopathies often encode protein components of the skeletal muscle contractile apparatus the sarcomere and proteins involved in.
Also, myopathies are usually nonprogressive that is, a myopathy usually doesnt grow worse over a persons lifetime. This article uses a casebased approach to highlight the clinical features as well as. Muscular dystrophies are genetically transmitted diseases characterized pathologically by degeneration and loss of myofibers and clinically by inexorably progressive weakness and, many of them, by elevated ck. Pdf approach to the diagnosis of congenital myopathies q. The congenital myopathies are a group of genetic muscle disorders characterised clinically by hypotonia and weakness, usually from birth, and a. Congenital myopathies pediatrics msd manual professional edition. Congenital myopathies merck manuals professional edition. Fiber hypertrophy is seen in athletes and as compensatory phenomenon in neurogenic. Incidence the actual incidence of congenital myopathy is unknown. Prevalence of congenital myopathies in a representative.
Others have a later onset, with symptoms appearing in childhood or adulthood. North, md in this issue of seminars in pediatric neurology, each chapter will focus on the. Congenital myopathy refers to a group of muscle disorders that appear at birth or in infancy. But if you notice a lack of muscle tone or delayed motor skills as your baby grows, let your childs doctor know about your concerns. A correct diagnostic approach requires the integration of data from. Congenital myopathies are severe muscle disorders affecting adults as well as children in all populations. Congenital myopathy is a term sometimes applied to hundreds of distinct neuromuscular disorders that may be present at birth, but it is usually reserved for a group of rare, inherited, primary muscle disorders that cause hypotonia and weakness at birth or during the neonatal period and, in some cases, delayed motor development later in childhood.
Typically, an infant with a congenital myopathy will be floppy, have difficulty breathing or feeding, and will lag behind other babies in meeting normal developmental milestones such as turning over or sitting up. An overview of congenital myopathies stony brook school of. Approach to the diagnosis of congenital myopathies. Clinical approach to the diagnosis of congenital myopathies. Congenital myopathies pediatrics msd manual professional. Differential diagnosis of distal myopathies practical neurology. Congenital myopathies refer to a heterogeneous group of genetic ne. Most congenital myopathies can be caused by mutations in more than one gene, and many of the causative genes are associated with more than one histologic diagnosis goebel, see pages 2215 in this issue. This article summarizes the clinical and genetic aspects of these disorders. Congenital myopathies netherlands pdf ppt case reports. Congenital myopathies are a heterogenous group of hereditary primary muscle disorders that are present from birth, although their onset may be delayed until later in infancy or early childhood. Definition, classification, clinical features, investigations, management.
Congenital myopathy isolated neck extensor myopathy 7th decade or older weakness over days to wks. Definition, classification, clinical features, differential diagnosis, investigations, management. Differential diagnosis of distal myopathies practical. This defect primarily affects skeletal muscle fibres and causes muscular weakness andor hypotonia. Facts about myopathies muscular dystrophy association. Moreover, the majority of patients present with unspecific histological features, precluding purposive molecular. Consensus statement on standard of care for congenital myopathies, journal of child neurology, 2012. The relationship between each congenital myopathy, defined on histologic grounds, and the genetic cause is complex. Approach to the patient with a suspected inherited disorder of metabolism. The most common of these rare disorders are nemaline myopathy, central core disease, centronuclear myotubular myopathies, and congenital fiber type. In a child, the muscle fibers are rounded and in an adult, the.
An integrated diagnosis strategy for congenital myopathies plos. Pdf over the past decade there have been major advances in defining the genetic basis of the majority of congenital myopathy subtypes. Approach to the diagnosis of congenital myopathies article pdf available in neuromuscular disorders 242 january 20 with 1,470 reads how we measure reads. Congenital myopathies metabolic myopathies mitochondrial myopathies muscular dystrophies myotonias acquired druginduced myopathies endocrine myopathies in. Myopathies can present with either constant weakness muscular dystrophies, inflammatory myopathies or episodic periods of weakness with normal strength interictally periodic paralysis, metabolic myopathies due to certain glycolytic pathway disorders. There can be significant clinical overlap between congenital myopathies and other neuromuscular disorders including the congenital muscular dystrophies cmd, congenital myotonic dystrophy, congenital myasthenic syndromes cms, metabolic myopathies including pompe disease, spinal muscular. We used exome sequencing complemented by histological and. Congenital myopathies etiology, pathophysiology, symptoms, signs, diagnosis. Muscle mri approach to congenital myopathies a and muscle mri t1weighted. Congenital myopathies metabolic myopathies mitochondrial myopathies acquired inflammatory myopathies. Moreover, the majority of patients present with unspecific histological features, precluding purposive molecular diagnosis and demonstrating the need for an alternative and more efficient diagnostic approach. Congenital muscular dystrophy and congenital myopathy. Advances in molecular genetics have allowed a more. Clinical and pathologic aspects of congenital myopathies.
However, different genes have now been identified as associated with the various. Onset in early life with hypotonia, hyporeflexia, generalized weakness that is more often proximal than dis. Approach to the diagnosis of congenital myopathies ncbi. Mar 27, 2019 congenital myopathy refers to a group of muscle disorders that appear at birth or in infancy. Over 30 genes causing muscular dystrophy are known. In this overview, we will provide an approach to the diagnosis of congenital myopathies and a guide to identifying the genetic basis for an individual patient based on clinical clues, muscle imaging mri and histological features on muscle biopsy. Approach to patients with neuromuscular disease aaem. Amato, md chief, neuromuscular division and director, clinical neurophysiology laboratory. North kn, wang ch, clarke n, jungbluth h, vainzof m, dowling jj, amburgey k, quijanoroy s, beggs ah, sewry c, et al. The pattern of weakness, tempo of evolution, and mode of inheritance vary among different dystrophies. Since that time, other myopathies have been defined as congenital myopathies, which have the following characteristics. Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by earlyonset muscle weakness. 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.
Core myopathies are characterized by regions cores on muscle biopsy specimens in which oxidative enzyme staining is absent. Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by earlyonset muscle weakness, hypotonia. Pdf approach to the diagnosis of congenital myopathies. In fact, some children with myopathies gain strength as they grow older. It is acknowledged that the increasing use of exome, targeted subexomic. Approach to patients with neuromuscular disorders anthony a. Findings detected only by em are seldom of clinical importance. Review article stony brook school of medicine homepage. Mar 11, 2019 the first report of a congenital myopathy was in 1956, when a patient with central core disease ccd was described. The episodic disorders have acute weakness that can return to normal strength within hours.
Congenital myopathy is a very broad term for any muscle disorder present at birth. In the current study, we have taken such an approach by performing an epidemiologic analysis of the prevalence of congenital myopathies in the pediatric population of southeastern michigan. Although the clinical symptoms closely mimic each other, the genetic basis differs from disease to disease. Patients with mg usually fatigue during repetitive activity while patients with lems can actually improve with continapproach to patients with neuromuscular disorders anthony a. One approach for overcoming these problems is to examine a welldefined subset of the population. Approach to a case of floppy infant congenital muscular dystrophy. Distal myopathies comprise a rare and heterogeneous group of disorders that present with weakness of the distal muscles of the hands, feet, or both. Clinical assessment should aim to distinguish proximal myopathy from other conditions that can present similarly, identify patients who need prompt attention, like those with cardiac, respiratory or pharyngeal muscle involvement, and determine underlying cause of. Central core myopathy was the first congenital myopathy to be identified. Congenital myopathy information page national institute. Finally, laboratory testing that can be performed to confirm. Dull or burning neck pain some report deltoid weakness emg changes limited to cece ca d to o e rvical mid to lower and upper thoracic spine mri fatty replacement and atrophy of the paraspinal muscles.
Findings historically, diagnoses of congenital muscular dystrophy and congenital myopathy have been made by clinical features and histopathology. This task was supported by a grant from a foundation. In some congenital myopathies, selective respiratory muscle involvement can cause nocturnal hypoventilation even though patients are fully ambulant 9,10. Clarke and heinz jungbluth and mariz vainzof and james j. Mar 05, 2020 congenital myopathies are usually noticed at birth. Diagnostic delays are common and clinicians need a high index of suspicion to recognise and differentiate metabolic myopathies. Recent findings historically, diagnoses of congenital muscular dystrophy. A muscle cell is stimulated to contract by chemical signals sent from an adjoining nerve cell 1. Patients with mg usually fatigue during repetitive activity while patients with lems can actually improve with contin approach to patients with neuromuscular disorders anthony a. This article uses a casebased approach to highlight the clinical features as well as recent advances in molecular genetics, muscle imaging, and pathophysiology of the congenital myopathies. A patternbased approach to the interpretation of skeletal.
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