Introduction Historical Background and Definition The limb-girdle muscular dystrophies (LGMDs) are a diverse and heterogeneous group of disorders within the broader field of genetic muscle disease. The term LGMD was first formally introduced in the 1950s to include the category…
Early Onset Distal Myopathies Laing Distal Myopathy (LDM, MPD1) Clinical Phenotype Symptoms of ankle stiffness are usually observed in infancy before the child starts to walk. However, ankle dorsiflexion weakness may be very mild and remain unnoticed until later. Weakness…
Introduction Facioscapulohumeral muscular dystrophy (FSHD) is the third most common muscular dystrophy after dystrophinopathies and myotonic muscular dystrophy. It affects 1 in 15,000 to 20,000 individuals with an estimated prevalence of 4 to 7 per 100,000. FSHD was first described…
Introduction This chapter reviews the current management recommendations for the skeletal muscle predominant disorders caused by mutations in the dystrophin gene: Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and manifesting carriers of dystrophinopathy. Duchenne muscular dystrophy is the most…
Introduction Dystrophinopathies are X-linked recessive diseases related to dystrophin deficiency; the major ones are Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, and Becker muscular dystrophy (BMD). BMD has a presentation similar to that of DMD but…
Introduction The identification of several new genes responsible for different forms of congenital muscular dystrophies (CMD) has dramatically expanded our knowledge of the spectrum of these conditions and their pathogenesis, allowing a better characterization of the individual forms and of…
The congenital myopathies are a heterogeneous group of neuromuscular conditions defined by distinctive morphologic abnormalities in skeletal muscle ( Figure 28.1 ). These disorders typically present in infancy or early childhood with hypotonia and muscle weakness, and are usually nonprogressive,…
Background Juvenile myasthenia gravis is a major category of neuromuscular junction disorders that shares many pathophysiologic and clinical features with adult autoimmune myasthenia gravis, yet displays distinct demographic patterns, clinical features, and therapeutic challenges. These considerations underscore the need to…
Introduction Congenital myasthenic syndromes (CMS) are heterogeneous disorders in which the safety margin of neuromuscular transmission is compromised by one or more specific mechanisms. These syndromes are neither new nor uncommon. They were recognized by Rothbart, who in 1937 described…
Infant Botulism Botulism is derived from the Latin botulus , for sausage. Van Ermengem in 1897 isolated the spore-forming anaerobe Bacillus botulinum from the spleen of a victim and the contaminated ham involved. This toxigenic form of botulism is the…