What is Delta-Sarcoglycanopathy?
Delta-sarcoglycanopathy represents a spectrum of disorders that typically cause muscle weakness as a result of a deficiency of the protein, delta-sarcoglycan, in the dystrophin-glycoprotein complex, a component of the muscle system. Symptoms of the disease vary greatly from person to person, even among people in the same family. Some people with the disease can have a mild course where they are nearly asymptomatic, while others may have severe symptoms that can be fatal. Presentations of this condition are described below.
Limb-Girdle Muscular Dystrophy Type 2F
People with limb-girdle muscular dystrophy type 2F (LGMD2F) develop symptoms at variable ages, though symptoms tend to first present in childhood. LGMD2F does not affect intelligence or mental function; the primary symptom is progressive muscle weakness of the hip, shoulder, and abdomen. The rate at which the muscles weaken can vary, but many experience progressive weakness to a point where a wheelchair becomes necessary. Other features include enlarged calf muscles, contractures, winging of the shoulder blade, and scoliosis. Respiratory complications are associated with the sarcoglycanopathies, and up to 20% of individuals will have heart complications (e.g. arrhythmia, cardiomyopathy) - both of which may be a cause of death.
Dilated Cardiomyopathy Type 1L
Individuals have also been described with only dilated cardiomyopathy (weakening of the heart muscle).
How common is Delta-Sarcoglycanopathy?
There are numerous types of limb-girdle muscular dystrophy. Autosomal recessive LGMD has an estimated prevalence of 1 in 15,000 individuals and LGMD2F accounts for a small subset of all cases of LGMD, though this varies by region. LGMD2F is more common in the Brazilian population.
How is Delta-Sarcoglycanopathy treated?
There is no cure for delta-sarcoglycanopathy and few effective treatments. Physical therapy is often recommended to retain muscle strength and mobility for as long as possible. Stretching, mechanical aids, or surgery may aid in that goal. As muscles deteriorate, a ventilator may be required to aid breathing. Cardiac surveillance is recommended, and those who develop heart problems should consult with a cardiologist for symptomatic treatments.
What is the prognosis for a person with Delta-Sarcoglycanopathy?
The outlook for a person with delta-sarcoglycanopathy varies. Generally speaking, the earlier symptoms begin, the faster they progress. However, because symptoms and onset can be variable, prognosis can be variable. People with more severe symptoms can become wheelchair bound in their early teens and die in early adulthood, and other causes of early death include respiratory and cardiac complications.