Genetically transmitted neuromuscular disorder characterized by progressive proximal muscle weakness. It is characterized by a progressive muscle wasting that affects predominantly hip and shoulder muscles. The muscle weakness is generally symmetric, solely proximal, and very slow in progression. The age of onset is variable as it can be seen in childhood, adolescence, or young adulthood. However, it is usually established between 10 and 30 years of age.
Erb’s Muscular Dystrophy Syndrome; Erb’s Scapulohumeral Dystrophy; Erb’s Syndrome 1; LGMD Syndrome.
This medical congenital condition was first described by the prolific Dr Wilhelm E. Erb, a German Neurologist, who identified, classified, and treated a large number of muscular dystrophies. He also contributed significantly to medicine with several technical advances such as the use of electricity in the diagnosis and treatment of nervous disorders, and the first clinician to use the reflex hammer to study nerve conduction and spinal cord well-being.
There are two types and numerous variants of LGMD.
Limb-Girdle Muscular Dystrophy Type IA (Proximal Muscular Dystrophy): Autosomal dominant disorder characterized by adult onset of proximal muscle weakness, beginning in the hip girdle region and later progressing to the shoulder girdle region. Distal muscle weakness may occur later. Some affected individuals exhibit a distinctive nasal, dysarthric pattern of speech.
Limb-Girdle Muscular Dystrophy Type IB: Characterized by cardiac involvement and symmetrical weakness in the proximal lower-limb muscles before age 20 years. In the third or fourth decade, upper-limb muscles gradually become affected. Early contractures of the spine and contractures of elbows and Achilles tendons are minimal or late, distinguishing this disorder from Emery-Dreifuss muscular dystrophy.
Limb-Girdle Muscular Dystrophy Type IC: Characterized with onset of disease around age 5 years. Calf hypertrophy, mild-to-moderate proximal muscle weakness, multiple episodes of muscle cramps after physical effort, and serum creatinine kinase levels more than 4-to 25-fold normal values are present.
Limb-Girdle Muscular Dystrophy Type ID: Characterized with a slowly progressive LGMD. Onset is believed to occur between the second and sixth decade, with hip girdle involvement preceding shoulder girdle involvement. It is inherited as an autosomal dominant pattern.
Limb-Girdle Muscular Dystrophy Type IE: Characterized by severe dilated cardiomyopathy with conduction defect. The age of onset is during the adulthood period and most often presents as progressive and severe muscle weakness of the lower extremities. Other clinical features include progressive dyspnea over years, becoming very severe even at rest, syncopal episodes due to complete heart block, and sudden death. An echocardiography always demonstrates dilatation of all four chambers of the heart.
Limb-Girdle Muscular Dystrophy Type IF: Characterized by pelvic and shoulder girdle proximal weakness. Pelvic girdle impairment is more severe and occurs earlier than shoulder girdle weakness. Distal weakness often occurs later. Respiratory muscles are ...