Duchenne Muscular Dystrophy And Becker Muscular Dystrophy

Duchenne muscular dystrophy and Becker muscular dystrophy

Duchenne and Becker muscular dystrophy are X-linked recessively inherited diseases, which are characterized by a progressive proximal muscle weakness as a result of muscle fiber degeneration. The Becker muscular dystrophy has a later onset and milder symptoms. The diagnosis is suspected clinically and by analysis of the protein product (dystrophin) of the mutated gene confirmed. Treatment focuses on maintaining the body functions through physical therapy and the use of corsets and other orthopedic devices. In some patients with rapid clinical deterioration prednisone or deflazacort is given.

Duchenne and Becker muscular dystrophies are caused by mutations in the dystrophin gene, which is the largest known human gene locus on Xp21.2. In Duchenne muscular dystrophy, the mutation results in a fatal absence of dystrophin (<5%), a protein of the muscle cell membrane. When Becker muscular dystrophy, the mutation results in a production of pathological dystrophin or insufficient dystrophin.

Duchenne and Becker muscular dystrophy are X-linked recessively inherited diseases, which are characterized by a progressive proximal muscle weakness as a result of muscle fiber degeneration. The Becker muscular dystrophy has a later onset and milder symptoms. The diagnosis is suspected clinically and by analysis of the protein product (dystrophin) of the mutated gene confirmed. Treatment focuses on maintaining the body functions through physical therapy and the use of corsets and other orthopedic devices. In some patients with rapid clinical deterioration prednisone or deflazacort is given. Duchenne and Becker muscular dystrophies are caused by mutations in the dystrophin gene, which is the largest known human gene locus on Xp21.2. In Duchenne muscular dystrophy, the mutation results in a fatal absence of dystrophin (<5%), a protein of the muscle cell membrane. When Becker muscular dystrophy, the mutation results in a production of pathological dystrophin or insufficient dystrophin. Duchenne muscular dystrophy affecting 1 in 4700 live births male. The Becker muscular dystrophy affects 1 in 30,000 male live births. Female carriers can be asymptomatic elevated creatine kinase levels and possibly calf hypertrophy. Symptoms and complaints Duchenne muscular dystrophy This disorder typically manifests between the ages of 2 to 3 years. The weakness affects the proximal muscles, usually at the beginning of the lower extremities. The children have a watschelndes gait, toe walking and lordosis. You have difficulty running, jumping, climbing stairs and getting up from the floor. Children often fall, and therefore often have fractures in the arms or legs (in about 20% of patients). The weakness progresses steadily continued, and it comes to flexion of the extremities and scoliosis in almost all children. A fixed pseudohypertrophy (replacement enlarged muscle groups, especially the calf by connective tissue and fat) develops. Most children are dependent on a wheelchair at the age of 12 years and die at age 20 to the respiratory complications. The consequences of myocardial involvement include cardiomyopathy, conduction defects and arrhythmias. Such complications occur in about one-third of patients aged 14 and in all patients over 18 years, but since these patients can not move, a cardiac involvement is usually up in the late stages of the disease asymptomatic. About one-third of the cases, simple, non-progressive intellectual disorders that language over the written expression betreffen.Becker dystrophy This disorder is much later symptomatic and runs easily. Walking normally remains until the age of 15 years receive, and many patients can go well into adulthood. Affected children survive until the fourth or fifth decade. Diagnostic muscle biopsy with Dystrophinanalyse by immunostaining DNA mutation analysis The diagnosis is suspected because of the characteristic clinical findings, age at onset and the family history of X-linked inheritance. The muscle changes can (recruited fast, short, niederamplitudige potentials) in EMG and be found by muscle biopsy (necrosis and increased variability in fiber size, which is not separated from the motor unit). The creatine kinase levels are increased by 100 times. The diagnosis is confirmed by the detection of dystrophin with immunostaining of biopsy specimens. In patients with Duchenne muscular dystrophy no dystrophin is found. In the Becker muscular dystrophin pathologically (lower molecular weight) or only in very low concentration is present. Mutation analysis of DNA from peripheral blood lymphocytes, the diagnosis can also confirm. It shows interference in the dystrophin gene: deletions at approximately 70% of patients with Duchenne muscular dystrophy and 85% in patients with Becker muscular dystrophy, as well as duplications at about 10% of the patients in both disorders. In patients with Duchenne dystrophy should be a fundamental assessment of cardiac function by ECG and echocardiography as soon as the diagnosis is made or at the age of 6 years. The identification of the carrier and a prenatal diagnosis can be determined by conventional methods such. B. family tree, creatine kinase determination and fetal sex determination in conjunction with a recombinant DNA analysis and dystrophin immunostaining in muscle tissue. Therapy Supportive tests Sometimes prednisone or deflazacort Sometimes in cardiomyopathy, an ACE inhibitor and / or ?-blockers Sometimes surgery Specific treatment is not there. A gentle, active movement is supported as long as possible, to prevent muscle atrophy or complications of inactivity. Passive exercises can prolong the period of walking ability. Orthopedic interventions should aim at maintaining the function and prevention of contractures. Ankle-foot orthotics that are worn at night can help prevent flexion contractures. Greaves may temporarily help when walking or standing. Surgical correction is sometimes necessary, especially with scoliosis. Obesity should be avoided, the calorie requirement is due to the reduced movement lower than normal. The respiratory failure can with non-invasive respiratory support (such as face masks, status asthmaticus (SA).) Are treated. An elective tracheotomy is increasingly accepted and allows children with Duchenne muscular dystrophy survival to the 3rd decade of life. In children with cardiomyopathy an ACE inhibitor and / or a ?-blockers can help prevent the progression or slow. In Duchenne muscular dystrophy is daily prednisone or deflazacort for patients> 5 years, who have no growth, or those drawn with decreasing motor skills into consideration. These drugs begin their effectiveness after at least 10 days after initiation of therapy; the effectiveness peaked at 3 months and lasts for 6 months. The long-term use increases the ambulatory treatment by 3 to 4 years, the time-fitted function tests improved (a measure of how quickly a child closes a functional object such as walking or getting up from the ground), the lung function, reduced obtains orthopedic complications and stabilized heart function. Prednisone on alternate days is not effective. Weight gain and Cushing’s face are common side effects after 6-18 months. The risk of vertebral fractures and fractures of the long bones is also increased. An application of prednisone or deflazacort in Becker dystrophy has not been adequately studied. Genetic therapy is not yet available at this stage. Genetic counseling is indicated (Prenatal genetic counseling and assessment). Important Points Duchenne and Becker muscular dystrophies are X-linked recessive disorders, a decrease of dystrophin, a protein of the muscle cell membranes cause Patients have a significant, progressive muscle weakness, severe disability, including difficulty walking, frequent falls, cardiomyopathy and premature death due to respiratory failure. Active and passive movement is helpful, along with leg braces and ankle-foot orthoses. Daily prednisone or deflazacort can improve muscle strength and muscle mass in Duchenne muscular dystrophy, although side effects are common. An ACE inhibitor and / or a ?-blockers can help prevent progression of cardiomyopathy or slow. Mechanical ventilation (first non-invasive and invasive later) can help prolong life.

Health Life Media Team

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