Limb-girdle muscular dystrophy
The limb-girdle muscular dystrophies are a group of diseases that cause muscle weakness (myopathy) and wasting (atrophy). The muscles that are most affected are those closest to the center of the body (proximal muscles), specifically the muscles of the shoulders, upper arms, hips, and thighs. Signs and symptoms may appear as early as childhood and typically worsen over time.
The severity, age of onset, and specific features of limb-girdle muscle dystrophy vary among affected individuals, even among members of the same family.
In the early stages of limb-girdle muscular dystrophy, affected individuals may have an unusual walking gait, such as waddling or walking on the balls of their feet. Walking this way for an extended period of time can cause overgrowth (hypertrophy) of the calf muscles. Affected individuals may also have difficulty running. They may need to use their arms to push themselves up from a squatting position because of their weak thigh muscles. Over time, as myopathy and atrophy worsen, people with limb-girdle muscular dystrophy may require wheelchair assistance.
Muscle atrophy may cause changes in posture or in the appearance of the shoulders, back, and arms. In particular, weak shoulder muscles tend to make the shoulder blades (scapulae) "stick out" from the back, a sign known as scapular winging. Weak back muscles may also cause an affected individual to have an abnormally curved lower back (lordosis) or a spine that curves to the side (scoliosis). Some affected individuals develop joint stiffness (contractures) that can restrict movement in their hips, knees, ankles, or elbows.
A weakening of the heart muscle (cardiomyopathy) occurs in some people with limb-girdle muscular dystrophy. If the weakness affects the muscles needed for breathing, affected individuals may have mild to severe breathing problems. In some cases, affected individuals need a machine to help them breathe (mechanical ventilation).
Intelligence is generally not affected in people with limb-girdle muscular dystrophy. However, developmental delays and intellectual disabilities have been reported in some affected individuals who have signs and symptoms that are more severe or that appear earlier in life.
Other names
LGMD; Limb-girdle syndrome; Myopathic limb-girdle syndrome
Inheritance pattern
Autosomal dominant; Autosomal recessive
Related genes
PLEC; FKTN; TTN; COL6A1; COL6A2; COL6A3; SGCA; SGCB; SGCG; SGCD; CAPN3; DYSF; ANO5; POMT1; POMT2; FKRP; CRPPA; LAMA2; POGLUT1; DAG1; TCAP; HNRNPDL; DNAJB6; POPDC1; TRIM32; TNPO3; GMPPB; POMGNT1; TRAPPC11; POPDC3; POMGNT2
Source: MedlinePlus Genetics, U.S. National Library of Medicine.
