What is Delta-Sarcoglycanopathy?
Delta-sarcoglycanopathy, caused by harmful genetic changes (mutations) in the SGCD gene, is a group of disorders that typically cause muscle weakness. Symptoms of the disease vary greatly from person to person, even among individuals in the same family. Some individuals 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
Individuals with limb-girdle muscular dystrophy type 2F (LGMD2F) develop symptoms at variable ages, though symptoms tend to present in early childhood. LGMD2F does not affect intelligence or mental function; the primary symptom is worsening (progressive) muscle weakness of the hip, shoulder, and abdomen. The rate at which the muscles weaken can vary, but often results in a wheelchair becoming necessary. Other features include enlarged calf muscles, shortening and hardening of muscles leading to rigid joints (contractures), prominence (winging) of the shoulder blades, and curvature of the spine (scoliosis). Respiratory complications (seen in ~20% of affected individuals) or heart complications (e.g., arrhythmia, cardiomyopathy) are also associated with these conditions and may lead to death.
Dilated Cardiomyopathy Type 1L
Individuals have also been described with only weakening of the heart muscle (dilated cardiomyopathy).
How common is Delta-Sarcoglycanopathy?
The incidence of autosomal-recessive limb-girdle muscular dystrophy (LGMD) is 1 in 15,000 individuals, with LGMD2F accounting 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 helps retain muscle strength and mobility for as long as possible. Mobility aids, such as walkers, canes, braces, and wheelchairs, may become necessary. As muscles deteriorate, a machine that assists with breathing (a ventilator) may be needed. Cardiac surveillance is recommended, and individuals who develop heart problems should consult a heart specialist (cardiologist) for symptomatic treatments. Some individuals may need surgery if they develop scoliosis or contractures.
What is the prognosis for an individual with Delta-Sarcoglycanopathy?
The outlook for an individual with delta-sarcoglycanopathy varies. Generally, the earlier symptoms begin, the faster they progress. However, because symptoms and onset can be variable, prognosis can be variable. In individuals with more severe symptoms, use of a wheelchair may become necessary in their early teens and death may occur in early adulthood. Causes of early death include respiratory and cardiac complications.