Muscular Dystrophy is a disease with inborn genetic manipulation which damages and weakens muscular structure and strength over a period of time. It’s been observed that people with MD have missing or incorrect information passed by their genes during the production of an important protein known as dystrophin. This protein is required for normal muscular function of the body such as walking, swallowing, coordination, etc.
There are approximately thirty different forms of MD that vary in symptoms, problems and severity. As the disease is related to muscular weakness, it can be possible that babies, teens or adults can express muscular problems at any phase of their development. This severe form of MD is observed in babies, especially boys, who can experience the swift and severe muscle weakness and wasting typically resulting in death in their late teens to early twenties.
Prevalence of Muscular Dystrophy
An estimated one out of every 35,000 males have MD. In a different study, it’s estimated that almost 29 percent are using a wheelchair at the age of 9, 82 percent are using wheelchair support at the age of 14 and more than 90 percent use a wheelchair at twenty-four.
Studies show that one hundred percent live until 14 and 58 percent survive into their early twenties.
There are approximately thirty different MD variants, but nine forms of MD are more commonly reported.
Duchenne Muscular Dystrophy – The most common form of MD; almost half of the reported cases are suffering from DMD. This affects boys; the symptoms are usually observed during 2-3 years of age; the child becomes wheelchair bound at the age of 12 and typically dies of respiratory failure by his early twenties. This involves weakness of major involuntary muscles such as the heart and lungs and is the most severe of form of MD.
Becker Muscular Dystrophy –This form of MD is like DMD although much milder and its symptoms start very late with less severity. On average, people with BMD start expressing symptoms such as muscle breakdown and weakness by the start of adulthood. Sometimes, people with BMD also exhibit breathing disorders, heart, bone, muscles and joint problems.
Emery-Dreifuss Muscular Dystrophy – A very rare form of MD, typically expressed in late childhood to early teens. Symptoms include wastage of muscles, weakness and joint deformities with slow progression. In severe cases, sudden death may occur due to cardiac arrest.
Limb-girdle Muscular Dystrophy –A type of MD affecting boys and girls equally. It usually occurs in late childhood to middle age. The symptoms include muscle wastage in the shoulders, upper arms, around the thighs and hips. The progression of the disease is slow, but in later stages of life a wheelchair may be necessary.
Myotonic Muscular Dystrophy – A type of MD in which muscle relaxation can cause a problem. It occurs especially in teens. Several other problems can also be exhibited such as muscle weakness, wasting, cataracts and heart issues.
Congenital Muscular Dystrophy – A general term for all babies and children with MD. This is equally expressed in girls and boys. In rare cases, CMD can cause learning or intellectual disability.
Fasciocapulohumeral Muscular Dystrophy – A type of MD that occurs in both men and women but more common in men. One in three people with this type of MD is typically unaware of the condition until well into adulthood. The symptoms may include sleeping with their eyes slightly open, an inability to squeeze their eyes tightly, and an inability to bring their lips together.
Factors Responsible for Muscular Dystrophy
MD is a genetic disorder due to faulty expression of mutated genes. Almost 90 percent of the disorders are inherited from family history whereas 10 percent are expressed due to spontaneous changes in their mother’s egg or developing embryo that has been passed on to the next generation. A female who carries the faulty genes can pass the same on to the next generation. If the genes are being passed to daughters, they become the carrier of the same, whereas if the genes are being passed on to the males, they tend to express the symptoms.
Researchers could ultimately discover the abnormal gene which, when defective, can cause MD. The muscle protein associated with the gene abnormality is known as dystrophin. In some cases, the protein is being produced but it’s either not clear or of very poor quality. Scientists are working to discover the genetic defects that cause other forms of MD.
Symptoms Associated with MD
MD is a disease that can’t be diagnosed early in its progression; in fact, some children follow the normal pattern of development during the first few years of their life. Slowly and over time, they start developing problems in little things such as climbing a staircase, walking on their toes, etc. A child may start to stumble, waddle or have difficulty in getting up from a sitting position. A child with MD often develops enlarged calf muscles due to fat replacements.
Prognosis of MD
A child must undergo a thorough physical examination followed by a detailed consultation of the family history. Some other tests are used to determine the type of MD. The doctor may suggest a blood test to determine if there are genetic problems.
What Goes Wrong in MD?
MD is a type of neuromuscular disorder that progressively damages the healthy muscles causing them to be weak and wasted. The disease is a form of congenital abnormality due to the wrong expression of faulty genes. Muscles and membranes need many different proteins to be strong and function properly. Some of these proteins are supplied to our body from the food we eat but some are synthesized by our body, such as dystrophin. This information regarding the production and the amount of protein is being passed on by our genetic makeup. In people with muscular dystrophy, due to gene mutation, wrong information is passed from one generation to another because these important proteins are not being produced or being produced in very low quantities.
Without these proteins, muscles lose their structural and functional integrity slowly and progressively, which may affect the overall normal functioning of the body.