Muscular dystrophy - AbsoluteAstronomy.com

Muscular dystrophy is a group of muscle diseases that weaken the musculoskeletal system and hamper locomotion. Muscular dystrophies are characterized by progressive skeletal muscle

Skeletal muscle

Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...

weakness, defects in muscle protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, and the death of muscle cells

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

and tissue

Biological tissue

Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

.

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

Guillaume Duchenne

Guillaume-Benjamin-Amand Duchenne was a French neurologist who revived Galvani's research and greatly advanced the science of electrophysiology...

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

Duchenne muscular dystrophy

Duchenne muscular dystrophy is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficulty walking, breathing, and death. The incidence is 1 in 3,000 boys. Females and males are affected, though females are rarely affected and are more often carriers...

.

It soon became evident that the disease had more than one form. The other major forms are Becker

Becker's muscular dystrophy

Becker muscular dystrophy is an X-linked recessive inherited disorder characterized by slowly progressive muscle weakness of the legs and pelvis....

, limb-girdle

Limb-girdle muscular dystrophy

Limb-girdle muscular dystrophy or Erb's muscular dystrophy is an autosomal class of muscular dystrophy that is similar but distinct from Duchenne muscular dystrophy and Becker's muscular dystrophy...

,
congenital

Congenital muscular dystrophy

Congenital muscular dystrophy is the term used to describe muscular dystrophy that is present at birth. CMD describes a number of autosomal recessive diseases of muscle weakness and possible joint deformities, present at birth and slowly progressing...

, facioscapulohumeral

Facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy , which is also known as Landouzy-Dejerine, is a usually autosomal dominant inherited form of muscular dystrophy that initially affects the skeletal muscles of the face , scapula and upper arms...

, myotonic, oculopharyngeal

Oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy is an autosomal dominant neuromuscular disease which appears in early middle age . OPMD is an example of a trinucleotide repeat disorder caused by expanding 10 to 11-17 at the 5' end of the coding region for PABPN1...

, distal

Distal muscular dystrophy

Distal muscular dystrophy is a group of disorders characterized by onset in the hands or feet.Many types involve dysferlin, but it has been suggested that not all cases do.Types include:...

, and Emery-Dreifuss

Emery-Dreifuss muscular dystrophy

Emery–Dreifuss muscular dystrophy is a condition that chiefly affects muscles used for movement and heart muscle.It is named after Alan Eglin H. Emery and Fritz E. Dreifuss.-Presentation:...

muscular dystrophy. These diseases predominately affect males, although females may be carriers of the disease gene. 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, 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.

Signs and symptoms

Progressive muscular wasting
Poor balance
Drooping eyelids
atrophy
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
Scoliosis
Scoliosis
Scoliosis is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C" than a straight line...

(curvature of the spine and the back)
Inability to walk
Frequent falls
Waddling gait
Calf deformation
Limited range of movement
Respiratory difficulty
Joint contractures
cardiomyopathy
Cardiomyopathy
Cardiomyopathy, which literally means "heart muscle disease," is the deterioration of the function of the myocardium for any reason. People with cardiomyopathy are often at risk of arrhythmia or sudden cardiac death or both. Cardiomyopathy can often go undetected, making it especially dangerous to...
arrhythmias

Cause

These conditions are generally inherited, and the different muscular dystrophies follow various inheritance patterns. However, mutations of the dystrophin gene and nutritional defects (with no genetics history) at the prenatal stage are also possible in about 33% of people affected by DMD. The main cause of the Duchenne and Becker types of muscular dystrophy is the muscle tissue's cytoskeletal impairment to properly create the functional protein dystrophin

Dystrophin

Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex...

and dystrophin-associated protein complex

Dystrophin-associated protein complex

The dystrophin-associated protein complex is a multiprotein complex that includes dystrophin and the dystrophin-associated proteins.Many forms of muscular dystrophy are associated with disorders of the dystrophin-associated protein complex....

.

Dystrophin protein is found in muscle fibre membrane, acting like a spring. It joins the membrane actin filaments.
The protein is rod shaped around 150 nm in length, 3684 amino acids long, 427 kDa molecule weight. It is hydrophobic (repels water). Conformation is alpha-helical, allowing protein to act as a shock absorber, preventing overstress.
Dystrophin links actin (cytoskeleton) and dystroglycans of the muscle cell plasma membrane, known as the sarcolemma (extracellular).
Dystrophin functions in two ways; mechanical stabilisation and regulated calcium levels.

Diagnosis

The diagnosis of muscular dystrophy is based on the results of muscle biopsy

Muscle biopsy

In medicine, a muscle biopsy is a procedure in which a piece of muscle tissue is removed from an organism and examined microscopically. A biopsy needle is usually inserted into a muscle, wherein a small amount of tissue remains. Alternatively, an "open biopsy" can be performed by obtaining the...

, increased creatine phosphokinase (CpK3), electromyography

Electromyography

Electromyography is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph, to produce a record called an electromyogram. An electromyograph detects the electrical potential generated by muscle...

, electrocardiography and DNA analysis.

A physical examination and the patient's medical history will help the doctor determine the type of muscular dystrophy. Specific muscle groups are affected by different types of muscular dystrophy.

Often, there is a loss of muscle mass (wasting), which may be hard to see because some types of muscular dystrophy cause a build up of fat and connective tissue that makes the muscle appear larger. This is called pseudohypertrophy.

Management

There is no known cure for muscular dystrophy, although significant headway is being made with antisense oligonucleotides

Antisense therapy

Antisense therapy is a form of treatment for genetic disorders or infections.When the genetic sequence of a particular gene is known to be causative of a particular disease, it is possible to synthesize a strand of nuc acid that will bind to the messenger RNA produced by that gene and inactivate...

. Physical therapy

Physical therapy

Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...

, occupational therapy

Occupational therapy

Occupational therapy is a discipline that aims to promote health by enabling people to perform meaningful and purposeful activities. Occupational therapists work with individuals who suffer from a mentally, physically, developmentally, and/or emotionally disabling condition by utilizing treatments...

, orthotic intervention (e.g., ankle-foot orthosis), speech therapy and orthopedic instruments (e.g., wheelchair

Wheelchair

A wheelchair is a chair with wheels, designed to be a replacement for walking. The device comes in variations where it is propelled by motors or by the seated occupant turning the rear wheels by hand. Often there are handles behind the seat for someone else to do the pushing...

s and standing frame

Standing frame

A standing frame is assistive technology that can be used by a person who relies on a wheelchair for mobility...

s) may be helpful. Inactivity (such as bed rest

Bed rest

Bed rest is a medical treatment involving a period of consistent recumbence in bed. It is used as a treatment for an illness or medical condition, especially when prescribed or chosen rather than resulting from severe prostration or imminent death...

, sitting for long periods) and bodybuilding

Bodybuilding

Bodybuilding is a form of body modification involving intensive muscle hypertrophy. An individual who engages in this activity is referred to as a bodybuilder. In competitive and professional bodybuilding, bodybuilders display their physiques to a panel of judges, who assign points based on their...

efforts to increase myofibrillar hypertrophy can worsen the disease.

There is no specific treatment for any of the forms of muscular dystrophy. Physiotherapy, aerobic exercise

Aerobic exercise

Aerobic exercise is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process. Aerobic literally means "living in air", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism...

, low intensity anabolic steroid

Anabolic steroid

Anabolic steroids, technically known as anabolic-androgen steroids or colloquially simply as "steroids", are drugs that mimic the effects of testosterone and dihydrotestosterone in the body. They increase protein synthesis within cells, which results in the buildup of cellular tissue ,...

s, prednisone

Prednisone

Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...

supplements may help to prevent contracture

Contracture

A muscle contracture is a permanent shortening of a muscle or joint.. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy....

s and maintain muscle tone. Orthoses (orthopedic appliances used for support) and corrective orthopedic surgery

Orthopedic surgery

Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...

may be needed to improve the quality of life in some cases. The cardiac problems that occur with Emery-Dreifuss muscular dystrophy

Emery-Dreifuss muscular dystrophy

Emery–Dreifuss muscular dystrophy is a condition that chiefly affects muscles used for movement and heart muscle.It is named after Alan Eglin H. Emery and Fritz E. Dreifuss.-Presentation:...

and myotonic muscular dystrophy may require a pacemaker

Artificial pacemaker

A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart...

. The myotonia

Myotonia

Myotonia is a symptom of a small handful of certain neuromuscular disorders characterized by the slow relaxation of the muscles after voluntary contraction or electrical stimulation. Generally, repeated effort is needed to relax the muscles, and the condition improves after the muscles have warmed...

(delayed relaxation of a muscle after a strong contraction) occurring in myotonic muscular dystrophy may be treated with medications such as quinine

Quinine

Quinine is a natural white crystalline alkaloid having antipyretic , antimalarial, analgesic , anti-inflammatory properties and a bitter taste. It is a stereoisomer of quinidine which, unlike quinine, is an anti-arrhythmic...

, phenytoin

Phenytoin

Phenytoin sodium is a commonly used antiepileptic. Phenytoin acts to suppress the abnormal brain activity seen in seizure by reducing electrical conductance among brain cells by stabilizing the inactive state of voltage-gated sodium channels...

, or mexiletine

Mexiletine

Mexiletine belongs to the Class IB anti-arrhythmic group of medicines. It is used to treat arrhythmias within the heart, or seriously irregular heartbeats. It slows conduction in the heart and makes the heart tissue less sensitive. Dizziness, heartburn, nausea, nervousness, trembling, unsteadiness...

, but no actual long term treatment has been found.

Occupational therapy

Occupational therapy

assists the individual with MD in engaging in his/her activities of daily living

Activities of daily living

Activities of Daily Living is a term used in healthcare to refer to daily self-care activities within an individual's place of residence, in outdoor environments, or both...

(self-feeding, self-care activities, etc.) and leisure activities at the most independent level possible. This may be achieved with use of adaptive equipment or the use of energy conservation techniques. Occupational therapy may implement changes to a person's environment, both at home or work, to increase the individual's function and accessibility. Occupational therapists also address psychosocial changes and cognitive decline which may accompany MD, as well as provide support and education about the disease to the family and individual.

High dietary intake of lean meat

Meat

Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...

, sea food, pulses, milk

Milk

Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

, egg

Egg (food)

Eggs are laid by females of many different species, including birds, reptiles, amphibians, and fish, and have probably been eaten by mankind for millennia. Bird and reptile eggs consist of a protective eggshell, albumen , and vitellus , contained within various thin membranes...

, olive oil

Olive oil

Olive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...

, leafy vegetables, bell pepper, fiber

Fiber

Fiber is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread.They are very important in the biology of both plants and animals, for holding tissues together....

, wheat

Wheat

Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

, antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

s, fruits like blueberry, cherry etc is advised. Decreased intake of carbohydrates, fats, dairy foods such as butter and milk, and caffeinated and alcoholic beverages is advised.

Diagnosis, neurology, GI-nutrition, respiratory care, cardiac care, orthopedics, psychosocial, rehabilitation, and oral care form the integral part of disease management, all through the patient's life span.

Prognosis

The prognosis for people with muscular dystrophy varies according to the type and progression of the disorder. Some cases may be mild and progress very slowly over a normal lifespan, while others produce severe muscle weakness, functional disability, and loss of the ability to walk. Some children with muscular dystrophy die in infancy while others live into adulthood with only moderate disability. The muscles affected vary, but can be around the pelvis, shoulder, face or elsewhere. Muscular dystrophy can affect adults, but the more severe forms tend to occur in early childhood.

Types

Type	OMIM	Gene	Description
Becker's muscular dystrophy Becker's muscular dystrophy Becker muscular dystrophy is an X-linked recessive inherited disorder characterized by slowly progressive muscle weakness of the legs and pelvis....		DMD Dystrophin Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex...	Becker muscular dystrophy (BMD) is a less severe variant of Duchenne muscular dystrophy Duchenne muscular dystrophy Duchenne muscular dystrophy is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficulty walking, breathing, and death. The incidence is 1 in 3,000 boys. Females and males are affected, though females are rarely affected and are more often carriers... and is caused by the production of a truncated, but partially functional form of dystrophin Dystrophin Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex... . Survival is usually into old age.
Congenital muscular dystrophy Congenital muscular dystrophy Congenital muscular dystrophy is the term used to describe muscular dystrophy that is present at birth. CMD describes a number of autosomal recessive diseases of muscle weakness and possible joint deformities, present at birth and slowly progressing...	Multiple	Multiple	Age at onset: birth; symptoms include general muscle weakness and possible joint deformities; disease progresses slowly; shortened life span. Congenital muscular dystrophy includes several disorders with a range of symptoms. Muscle degeneration may be mild or severe. Problems may be restricted to skeletal muscle, or muscle degeneration may be paired with effects on the brain and other organ systems. A number of the forms of the congenital muscular dystrophies are caused by defects in proteins that are thought to have some relationship to the dystrophin-glycoprotein complex and to the connections between muscle cells and their surrounding cellular structure. Some forms of congenital muscular dystrophy show severe brain malformations, such as lissencephaly Lissencephaly Lissencephaly, which literally means smooth brain, is a rare brain formation disorder caused by defective neuronal migration during the 12th to 24th weeks of gestation, resulting in a lack of development of brain folds and grooves . It is a form of cephalic disorder... and hydrocephalus Hydrocephalus Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,... .
Duchenne muscular dystrophy Duchenne muscular dystrophy Duchenne muscular dystrophy is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficulty walking, breathing, and death. The incidence is 1 in 3,000 boys. Females and males are affected, though females are rarely affected and are more often carriers...		DMD Dystrophin Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex...	Duchenne muscular dystrophy (DMD) is the most common childhood form of muscular dystrophy, becoming clinically evident when a child begins walking. Patients typically require a wheelchair by age 10 to 12 and die in their late teens to early 20s, though some people with Duchenne muscular dystrophy are now living to age 40 and beyond. In the early 1990s, researchers identified the gene for the protein dystrophin Dystrophin Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex... which, when absent, causes DMD. The amount of dystrophin correlates with the severity of the disease (i.e. the less dystrophin present, the more severe the phenotype). Since the gene is on the X chromosome, this disorder affects primarily males, and females who are carriers have milder symptoms. Sporadic mutations in this gene occur frequently, accounting for a third of cases. The remaining two-thirds of cases are inherited in a recessive pattern. Dystrophin is part of a complex structure involving several other protein components. The "dystrophin-glycoprotein complex" helps anchor the structural skeleton (cytoskeleton) within the muscle cells, through the outer membrane (sarcolemma) of each cell, to the tissue framework (extracellular matrix) that surrounds each cell. Due to defects in this assembly, contraction of the muscle leads to disruption of the outer membrane of the muscle cells and eventual weakening and wasting of the muscle.
Distal muscular dystrophy Distal muscular dystrophy Distal muscular dystrophy is a group of disorders characterized by onset in the hands or feet.Many types involve dysferlin, but it has been suggested that not all cases do.Types include:...		DYSF Dysferlin Dysferlin also known as dystrophy-associated fer-1-like protein is a protein that in humans is encoded by the DYSF gene.Dysferlin is linked with skeletal muscle repair. A defect in the DYSF gene, located on chromosome 2p12-14, results in either of two types of muscular dystrophy; Miyoshi myopathy ...	Distal muscular dystrophies' age at onset: 20 to 60 years; symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs; progress is slow and not life-threatening. Miyoshi myopathy, one of the distal muscular dystrophies, causes initial weakness in the calf muscles, and is caused by defects in the same gene responsible for one form of LGMD (Limb Girdle Muscular Dystrophy) Limb-girdle muscular dystrophy Limb-girdle muscular dystrophy or Erb's muscular dystrophy is an autosomal class of muscular dystrophy that is similar but distinct from Duchenne muscular dystrophy and Becker's muscular dystrophy... .
Emery-Dreifuss muscular dystrophy Emery-Dreifuss muscular dystrophy Emery–Dreifuss muscular dystrophy is a condition that chiefly affects muscles used for movement and heart muscle.It is named after Alan Eglin H. Emery and Fritz E. Dreifuss.-Presentation:...	,	EMD Emerin Emerin, together with MAN1, is a LEM domain-containing integral membrane protein of the nuclear membrane in vertebrates. The function of MAN1 is not extensively known, but emerin is known to interact with nuclear lamins, barrier-to-autointegration factor , nesprin-1α, and a transcription... , LMNA LMNA Lamin A/C also known as LMNA is a protein that in humans is encoded by the LMNA gene. Lamin A/C belongs to the lamin family of proteins.-Function:...	Emery-Dreifuss Muscular Dystrophy patients normally present in childhood and the early teenage years with contractures. Clinical signs include muscle weakness and wasting, starting in the distal limb muscles and progressing to involve the limb-girdle muscles. Most patients also suffer from cardiac conduction defects and arrhythmias which, if left untreated, increase the risk of stroke and sudden death. There are three subtypes of Emery-Dreifuss Muscular Dystrophy, distinguishable by their pattern of inheritance: X-Linked, autosomal dominant and autosomal recessive. The X-linked form is the most common. Each type varies in prevalence and symptoms. The disease is caused by mutations in the LMNA gene, or more commonly, the EMD gene. Both genes encode for protein componenets of the nuclear envelope. However, how the pathogenesis of these mutations is not well understood.
Facioscapulohumeral muscular dystrophy Facioscapulohumeral muscular dystrophy Facioscapulohumeral muscular dystrophy , which is also known as Landouzy-Dejerine, is a usually autosomal dominant inherited form of muscular dystrophy that initially affects the skeletal muscles of the face , scapula and upper arms...		DUX4 DUX4 Double homeobox, 4 also known as DUX4 is a protein which in humans is encoded by the DUX4 gene.-Gene:This gene is located within a D4Z4 repeat array in the subtelomeric region of chromosome 4q. The D4Z4 repeat is polymorphic in length; a similar D4Z4 repeat array has been identified on chromosome 10...	Facioscapulohumeral muscular dystrophy (FSHD) initially affects the muscles of the face, shoulders, and upper arms with progressive weakness. Symptoms usually develop in the teenage years. Some affected individuals become severely disabled. The pattern of inheritance is autosomal dominant, but there are a significant number of spontaneous mutations. Seminal research published in August 2010 documents that two defects are needed for FSHD, which for the first time provides a unifying theory for the underlying genetics of FSHD. The first is the deletion of D4Z4 repeats and the second is a "toxic gain of function" of the DUX4 DUX4 Double homeobox, 4 also known as DUX4 is a protein which in humans is encoded by the DUX4 gene.-Gene:This gene is located within a D4Z4 repeat array in the subtelomeric region of chromosome 4q. The D4Z4 repeat is polymorphic in length; a similar D4Z4 repeat array has been identified on chromosome 10... gene. Facioscapulohumeral muscular dystrophy (FSHD) occurs both in males and females.
Limb-girdle muscular dystrophy Limb-girdle muscular dystrophy Limb-girdle muscular dystrophy or Erb's muscular dystrophy is an autosomal class of muscular dystrophy that is similar but distinct from Duchenne muscular dystrophy and Becker's muscular dystrophy...	Multiple	Multiple	Limb-girdle muscular dystrophy is also called LGMD. LGMDs all show a similar distribution of muscle weakness, affecting both upper arms and legs. Many forms of LGMD have been identified, showing different patterns of inheritance (autosomal recessive vs. autosomal dominant). In an autosomal recessive pattern of inheritance, an individual receives two copies of the defective gene, one from each parent. The recessive LGMDs are more frequent than the dominant forms, and usually have childhood or teenage onset. The dominant LGMDs usually show adult onset. Some of the recessive forms have been associated with defects in proteins that make up the dystrophin-glycoprotein complex. Death from LGMD is usually due to cardiopulmonary complications.
Myotonic muscular dystrophy	,	DMPK, ZNF9	Myotonic MD's age at onset: 20 to 40 years Myotonic muscular dystrophy is the most common adult form of muscular dystrophy. It is marked by myotonia Myotonia Myotonia is a symptom of a small handful of certain neuromuscular disorders characterized by the slow relaxation of the muscles after voluntary contraction or electrical stimulation. Generally, repeated effort is needed to relax the muscles, and the condition improves after the muscles have warmed... as well as muscle wasting and weakness. Myotonic dystrophy varies in severity and manifestations and affects many body systems in addition to skeletal muscles, including the heart, endocrine organs, eyes, and gastrointestinal tract. Myotonic dystrophy follows an autosomal dominant pattern of inheritance. Myotonic dystrophy results from the expansion of a short repeat in the DNA sequence (CTG in one gene or CCTG in another gene). In other words, the gene defect is an abnormally long repetition of a three- or four-letter "word" in the genome Genome In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA.... . While the exact mechanism of action is not known, this molecular change may interfere with the production of important muscle proteins.
Oculopharyngeal muscular dystrophy Oculopharyngeal muscular dystrophy Oculopharyngeal muscular dystrophy is an autosomal dominant neuromuscular disease which appears in early middle age . OPMD is an example of a trinucleotide repeat disorder caused by expanding 10 to 11-17 at the 5' end of the coding region for PABPN1...		PABPN1 PABPN1 Polyadenylate-binding protein 2 also known as polyadenylate-binding nuclear protein 1 is a protein that in humans is encoded by the PABPN1 gene.- Function :...	Oculopharyngeal MD's age at onset: 40 to 70 years; symptoms affect muscles of eyelids, face, and throat followed by pelvic and shoulder muscle weakness, has been attributed to a short repeat expansion in the genome Genome In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA.... which regulates the translation of some genes into functional proteins.

Research funding

Within the United States, the three primary federally funded organizations that focus on muscular dystrophy research (Gene therapy

Gene therapy

Gene therapy is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease. It is a technique for correcting defective genes that are responsible for disease development...

, Regenerative medicine

Regenerative medicine

Regenerative medicine is the "process of replacing or regenerating human cells, tissues or organs to restore orestablish normal function". This field holds the promise of regenerating damaged tissues and organs in the body by replacing damaged tissue and/or by stimulating the body's own repair...

) etc include the National Institute of Neurological Disorders and Stroke

National Institute of Neurological Disorders and Stroke

The National Institute of Neurological Disorders and Stroke is a part of the U.S. National Institutes of Health . It conducts and funds research on brain and nervous system disorders and has a budget of just over US$1.5 billion...

(NINDS), National Institute of Arthritis and Musculoskeletal and Skin Diseases

National Institute of Arthritis and Musculoskeletal and Skin Diseases

The National Institute of Arthritis and Musculoskeletal and Skin Diseases, or NIAMS, is an institute of the National Institutes of Health, an agency of the United States Department of Health and Human Services...

(NIAMS), and National Institute of Child Health and Human Development

National Institute of Child Health and Human Development

The Eunice Kennedy Shriver National Institute of Child Health and Human Development , created by Congress in 1962, supports and conducts research on topics related to the health of children, adults, families, and populations...

(NICHD).

In 1966, the Muscular Dystrophy Association

Muscular Dystrophy Association

The Muscular Dystrophy Association is an American organization which combats muscular dystrophy and diseases of the nervous system and muscular system in general by funding research, providing medical and community services, and educating health professionals and the general public...

began its annual Jerry Lewis MDA Telethon

Jerry Lewis MDA Telethon

The MDA Labor Day Telethon is an annual telethon in the United States to raise money for the Muscular Dystrophy Association . The first MDA telethon was during the Thanksgiving Day weekend of 1952 and titled Party for MDA. It has been held annually since 1966...

, which has arguably done more to raise awareness of muscular dystrophy than any other event or initiative. Disability rights advocates, however, have criticized the Jerry Lewis Telethon for portraying victims of the disease as deserving pity rather than respect.

On December 18, 2001 the MD CARE Act was signed into law and amends the Public Health Service Act

Public Health Service Act

The Public Health Service Act is a United States federal law enacted in 1944. The full act is captured under Title 42 of the United States Code "The Public Health and Welfare", Chapter 6A "Public Health Service"....

to provide research for the various muscular dystrophies. This law also established the Muscular Dystrophy Coordinating Committee to help focus research efforts through a coherent research strategy.

External links

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