Muscular Dystrophy (MD) is a group of muscle diseases that weaken the musculoskeletal system and hamper locomotion.Muscular dystrophies are characterized by progressive skeletal muscle weakness, defects in muscle proteins, and the death of muscle cells and tissue.
In the 1860s, descriptions of boys who grew progressively weaker, lost the ability to walk, and died at an early age became more prominent in medical journals. In the following decade, French neurologist Guillaume Duchenne gave a comprehensive account of thirteen boys with the most common and severe form of the disease, which now carries his name—Duchenne muscular dystrophy.
It soon became evident that the disease had more than one form. The other major forms are Becker, limb-girdle, congenital, facioscapulohumeral, myotonic, oculopharyngeal, distal, and Emery-Dreifuss muscular dystrophy. Duchenne and Becker muscular dystrophies, being caused by a mutation of a gene located on the X chromosome, predominantly affect males, although females can sometimes have severe symptoms as well. Most types of MD are multi-system disorders with manifestations in body systems including the heart, gastrointestinal system, nervous system, endocrine glands, eyes and brain.
Apart from the nine major types of muscular dystrophy listed above, several MD-like conditions have also been identified. Normal intellectual, muscular, behavioral, bowel and sexual function is noticed in individuals with other forms of MD and MD-like conditions. MD-affected individuals with susceptible intellectual impairment are diagnosed through molecular characteristics but not through problems associated with disability.However, a third of patients who are severely affected with DMD may have cognitive impairment, behavioral, vision and speech problems.