What is Muscular Dystrophy, LAMA2-related?
Muscular dystrophy (MD), LAMA2-related causes significant muscle weakness and wasting (atrophy). Harmful genetic changes (mutations) in the LAMA2 gene cause this condition. The LAMA2 gene is important to proper functioning of the skeletal and heart (cardiac) muscles, and mutations negatively affect this function. There is both an early-onset and late-onset form of muscular dystrophy, LAMA2-related.
Early-onset Muscular Dystrophy, LAMA2-related
Early-onset MD, LAMA2-related is the most common form of this condition. It is part of a group of muscle disorders called congenital muscular dystrophies (CMD). Symptoms start at birth or within the first few months of life and include severe low muscle tone (hypotonia) and muscle weakness. Because of this, infants have delayed motor milestones. Most individuals with this condition can sit unsupported, and some may stand without assistance, but very few are ever able to walk without help. In addition, muscle weakness also causes significant breathing difficulties that may worsen with age and feeding difficulties that result in poor growth (failure to thrive). Other symptoms may include frequent chest infections, shortening and hardening of muscles leading to rigid joints (contractures), progressive curvature of the spine (scoliosis), seizures, and cardiac issues. A small percentage of individuals with this condition experience intellectual disability.
Late-onset Muscular Dystrophy, LAMA2-related
The onset of symptoms in late-onset MD, LAMA2-related ranges from childhood to adulthood. This form tends to be milder than the early-onset type, and symptoms are like those of a group of muscle disorders called limb-girdle muscular dystrophies. In late-onset MD, LAMA2-related, the most affected muscles are those closest (most proximal) to the body, such as the shoulders, upper arms, pelvic area, and thighs. Individuals are usually able to walk without assistance. Other symptoms include rigidity of the back, joint contractures, and breathing problems. Seizures may occur in some individuals with this condition.
How common is Muscular Dystrophy, LAMA2-related?
The worldwide incidence of CMD is unknown, though studies of the northeastern Italian population estimate a frequency of 1 in 21,500. Mutations in LAMA2 are the most common cause of CMD worldwide. The proportion of CMD cases due to LAMA2 mutations varies by population, with LAMA2 mutations responsible for 30% of CMD cases in Europe but only 6% of cases in Japan.
How is Muscular Dystrophy, LAMA2-related treated?
Treatment is focused on alleviating symptoms, with the objective of optimizing each individual's abilities. For patients with early-onset MD, LAMA2-related, treatment may include physical therapy, occupational therapy, speech therapy, and supplemental feeding. Use of a machine that helps with breathing (a ventilator) may be required. Supportive devices such as a brace or splint (orthotics) may be used for joint stiffness. Individuals with the late-onset form often need physical therapy, and some require care for breathing difficulties. Seizures are often treated with medications, if necessary. Monitoring of respiratory (lung) and cardiac function may be recommended.
What is the prognosis for an individual with Muscular Dystrophy, LAMA2-related?
Due to the serious health problems that occur in the early-onset form of the disorder, especially breathing issues, many individuals do not survive past adolescence. Those with the rarer, late-onset form have progressive muscle weakness, but life expectancy is often normal.