Muscular dystrophy (MD) can be defined as a group of genetic disorders that causes weakening of muscles. Muscle fibers are more susceptible to this disease. Voluntary muscles are mostly affected by it. However, in some types of MD, heart muscles and other involuntary muscles are also affected. A genetic deficiency of muscle protein, called dystrophin, is the main cause of most types of muscular dystrophy.
This condition can be categorized into nine major types, depending upon the location of muscles involved, the age that the symptoms start, the rate that the symptoms progress, and the manner in which the defective gene is passed on. Each type is caused by the mutation of a defective gene.
Some of the most common types of MD are dystrophinopathies, Duchenne Muscular Dystrophy (DMD), Becker Muscular Dystrophy (BMD), myotonic dystrophy, facioscapulohumeral muscular dystrophy, limb-girdle muscular dystrophy, congenital muscular dystrophy, distal muscular dystrophy, oculopharyngeal muscular dystrophy, and Emery-Dreifuss muscular dystrophy.
Symptoms: An Overview
The signs of this medical condition may vary depending upon the types of muscular dystrophy. Each form of MD is different in terms of age of onset, body part affected, and progression of symptoms. Some of the common symptoms are muscle pain and weakness, loss of function, difficulty in walking, frequent falls, calf pain, waddling gait, obesity, and joint contractures, drooping eyes, and mental impairment. Each form of MD shows some different symptoms such as:
Duchenne muscular dystrophy
It is the most severe type of MD. It most commonly affects children and young boys. Some common signs and symptoms of this type are frequent falls, large calf muscles, waddling gait, weakness in lower leg muscles, causing difficulty in jumping and running, difficulty in getting up from a sitting or lying position, and in some cases, and mental retardation.
Becker's muscular dystrophy
This type affects older boys and young men. It progresses very slowly. The onset of symptoms is at the age of 11. Their symptoms are similar to those of Duchenne muscular dystrophy.
Facioscapulohumeral muscular dystrophy
It is also referred to as Landouzy-Dejerine disease. This form causes progressive weakness of muscles of face, shoulders, abdomen, feet, upper arm, pelvic area, and lower arms.
This type of MD is also called Steinert's disease. It causes stiffness of muscles, muscle weakness, and inability to relax muscles. Some common signs and symptoms of myotonic dystrophy are weakening of voluntary muscles that control one's arms and legs, weakening of face, neck, and head muscles, weakening of muscles that are involved in swallowing and breathing, and weakening of muscles of the hollow internal organs. Other symptoms are dizziness or fainting, difficulty in sleeping at night, daytime sleepiness, cataracts, and frontal balding in men.
Congenital muscular dystrophy
This type of MD is apparent at birth and progresses gradually. The symptoms involve general muscle weakness and joint deformities. More severe type of congenital MD causes severe mental and speech problems.
Emery-Dreifuss muscular dystrophy
It starts in the muscles of the upper arms, shoulders, and shins. Stiffness of spine, cardiac arrhythmias, and muscle contractures are other symptoms of this type.
Distal muscular dystrophy
This form affects the muscles farthest away from the center of the body. They include the muscles of forearms, hands, feet, and lower legs. It is relatively a less severe form of MD and progresses slowly. The symptoms generally start in the adulthood, between the ages of 40 and 60.
The symptoms of some forms of MD appear in infancy or childhood, while in some cases it may not appear until middle age. If one is unable to recognize the symptoms of this particular disease, it's advisable that one visits a health practitioner as soon as possible.
Disclaimer: This HealthHearty article is for informative purposes only, and should not be used as a replacement for expert medical advice.