Beta-sarcoglycanopathy

Overview

An autosomal recessive form of limb-girdle muscular dystrophy where muscle weakness and atrophy is caused by mutations of the beta-sarcoglycan gene. The severity of the condition is greatly variable from wheelchair confinement at the age of 9 years to asymptomatic adults. Most tend to live to their third decade.

Symptoms

* Weakness * Toe walking * Muscle pain * Muscle cramps * Shoulder girdle muscle weakness * Shoulder girdle muscle wasting * Scapular muscle weakness * Scapular muscle wasting * Lordosis * Foot drop * Loss of mobility * Hamstring muscle weakness * Hamstring muscle wasting * Quadricep muscle weakness * Quadricep muscle wasting * Delayed motor milestone delay * Delayed motor milestones * Calf muscle hypertrophy * Abnormal curvature of the spine

Causes

Muscular dystrophy is caused by various genetic mechanisms. Duchenne’s and Becker’s muscular dystrophies are X-linked recessive disorders. Both result from defects in the gene coding for the muscle protein dystrophin; the gene has been mapped to the Xp21 locus. The incidence muscular dystrophy is about 1 in 651,450 persons in the United States. Duchenne’s and Becker’s muscular dystrophies affect males almost exclusively. Facioscapulohumeral dystrophy is an autosomal dominant disorder. Limb-girdle dystrophy is usually autosomal recessive. These two types affect both sexes about equally.

Prognosis

Prognosis of Limb-girdle muscular dystrophy type 2E: severe cases are confined to wheelchair by 13 years whereas as milder cases are capable of walking even after 16 years of age

Treatment

No treatment stops the progressive muscle impairment of muscular dystrophy. However, orthopedic appliances, exercise, physical therapy, and surgery to correct contractures can help preserve the patient’s mobility and independence. Prednisone improves muscle strength in patients with Duchenne’s.

Resources

Beta-sarcoglycanopathy: Another name for Limb-girdle muscular dystrophy type 2E