Muscular dystrophy: A group of genetic disorders that affect the muscles

Muscular dystrophy is a term that refers to a group of more than 30 genetic disorders that cause progressive weakness and loss of muscle mass. These disorders are caused by mutations in genes that are involved in the production of proteins that are essential for the normal functioning of muscle cells.

Depending on the type and severity of the mutation, muscular dystrophy can affect different muscle groups, different organs, and different aspects of health and quality of life.

The most common and severe form of muscular dystrophy is Duchenne muscular dystrophy (DMD),which mainly affects boys and usually manifests in early childhood. DMD is caused by a mutation in the gene that encodes dystrophin, a protein that helps to maintain the structure and stability of muscle fibers. Without dystrophin, muscle cells become damaged and die, leading to muscle wasting and weakness.

DMD affects mainly the muscles of the limbs, trunk, and face, but also the heart and respiratory muscles, causing serious complications such as cardiomyopathy, arrhythmias, and respiratory failure. DMD has no cure and is usually fatal by the age of 30.

Another common form of muscular dystrophy is Becker muscular dystrophy (BMD), which is similar to DMD but less severe and more variable. BMD is also caused by a mutation in the dystrophin gene, but the mutation results in a reduced or altered production of dystrophin, rather than a complete absence.

BMD affects mainly boys and men, and the symptoms can range from mild to severe, depending on the amount and function of dystrophin. BMD can also affect the heart and respiratory muscles, but the onset and progression of the disease are slower than in DMD.

Myotonic dystrophy is the most common form of muscular dystrophy that affects adults of both sexes. It is caused by a mutation in the gene that encodes myotonic dystrophy protein kinase (DMPK), a protein that regulates muscle contraction and relaxation. The mutation causes an abnormal expansion of a repeated DNA sequence in the gene, which leads to the accumulation of toxic RNA molecules in the muscle cells.

These molecules interfere with the function of other proteins that are involved in muscle, heart, brain, and endocrine function. Myotonic dystrophy is characterized by muscle stiffness, weakness, and wasting, as well as by various systemic symptoms such as cataracts, cardiac arrhythmias, diabetes, and cognitive impairment.

Other forms of muscular dystrophy include congenital muscular dystrophies, which are present at birth or develop in early childhood; distal muscular dystrophies, which affect the muscles of the hands, feet, lower arms, and lower legs; Emery-Dreifuss muscular dystrophy, which affects the muscles of the shoulders, upper arms, and shins, as well as the heart;

facioscapulohumeral muscular dystrophy, which affects the muscles of the face, shoulders, and upper arms; and limb-girdle muscular dystrophy, which affects the muscles of the hips, shoulders, upper arms, and upper legs.

The diagnosis of muscular dystrophy is based on the medical history, physical examination, blood tests, muscle biopsy, genetic tests, and imaging tests. The treatment of muscular dystrophy is aimed at managing the symptoms, preventing complications, and improving the quality of life of the patients.

There is no cure for muscular dystrophy, but some medications, such as corticosteroids, can help slow down the progression of muscle weakness and improve muscle function. Other medications, such as antiarrhythmics, can help to treat the cardiac problems associated with some forms of muscular dystrophy.

Physical therapy, occupational therapy, speech therapy, respiratory therapy, and orthopedic surgery can also help to maintain muscle strength, mobility, and function, as well as to correct deformities and prevent contractures. Assistive devices, such as braces, wheelchairs, and ventilators, can also help to improve the independence and comfort of the patients.

Muscular dystrophy is a group of genetic disorders that affect the muscles and cause progressive weakness and loss of muscle mass. The symptoms, causes, and treatments of muscular dystrophy vary depending on the type and severity of the disorder. Muscular dystrophy is a serious and life-threatening condition that requires ongoing medical care and support.