Duchenne muscular dystrophy is a malignant muscle disease based on a gene defect on the X chromosome, so that the disease can only occur in male offspring. The symptoms are already in infancy in the form of weaknesses in the pelvic and thigh muscles. It always ends fatally in early adulthood by reducing the heart and lung muscles.

What is Duchenne Muscular Dystrophy?

Muscular dystrophy type Duchenne (DMD) is a progressive muscle weakness, which is based on a gene defect on the "male" X chromosome. Because the gene defect is located on the X chromosome, the disease can only occur in male family members.

For them, however, it is pure, because the gene on whose mutation the disease is based occurs only once and can not be compensated by a second gene - as usual in a diploid chromosome set usual. This means that male offspring will definitely become ill with DMD in the presence of the genetic defect.

The DMD shows itself in the early age between the first and sixth year by muscle weakness and muscle loss in the pelvic and leg muscles. The disease itself is caused by a synthesis disorder of the protein dystrophin. Dystrophin is an important and functional component of the membrane that surrounds the muscle fibers (sarcolemma). DMD is the most common form of all known muscular dystrophies.

causes

On the X chromosome is the so-called DMD gene, which is responsible for the coding of the protein dystrophin. At 2.5 million base pairs, it is the largest known gene in the human genome and is therefore susceptible to mutations that usually completely block the synthesis of dystrophin.

The mutation of the DMD gene may be the loss (deletion) of a segment (multiple base pairs), a duplication, or a point mutation involving only a single nucleobase. The mutations trigger various forms of muscle weakness, of which Duchenne muscular dystrophy is by far the most common manifestation.

It is noteworthy that in about one-third of DMD-affected boys, the disease was caused by a new mutation and not inherited by the mother. This explains why DMD does not significantly diminish in frequency of occurrence.

Symptoms, complaints & signs

The Duchenne muscular dystrophy (DMD) manifests in the first years of life and has its beginning in the pelvic girdle area. Toddlers have difficulty walking, running unsteadily, stumbling and falling more frequently. You are not able to run fast. Due to the weakened thigh muscles, they can not sit up alone, but rely on their thighs when raising their hands.

This characteristic symptom is also called Gower's sign. People with Duchenne muscular dystrophy (DMD) show an increase in connective and adipose tissue, especially in the calf area. That's why her calves seem unusually strong.

In medical terminology, thickened calves are called gnomes. Furthermore, in patients with Duchenne muscular dystrophy (DMD), pointed feet and pronounced curvature of the spine in the lumbar region can be observed.

The Duchenne muscular dystrophy (DMD) progresses rapidly, so that the majority of patients are dependent on a wheelchair and all-day care before the age of 12. In the advanced stage of the disease it comes through a weakness of the respiratory muscles to breathing difficulties. Furthermore, sufferers have diminished reflexes and suffer from sensory disturbances. About one third of the patients also have an intellectual disability.

Diagnosis & disease course

If the initial suspicion is confirmed, neurological examinations and functional tests of the muscles are indicated. Imaging techniques such as MRI and ultrasound can provide further information. Often, an elevated level of the muscle enzyme creatine kinase can be detected in the blood. Ultimate certainty creates genetic diagnosis, which also allows the allocation of muscular dystrophy to one of the known manifestations.

The course of the DMD is progressive. From the fifth to the seventh year of life, those affected can usually no longer stand up unassisted from sitting or lying down and no longer climb stairs. The muscle wasting leads to deformations of the joints and deposits of fatty tissue in the muscles as a replacement for the muscle tissue. As a rule, children from the 10th to the 12th year are dependent on a wheelchair. The life expectancy is about 40 years, although a previous death before the onset of puberty can not always be prevented.

complications

As a rule, Duchenne muscular dystrophy causes death of the patient. Death occurs at a very young age. Above all, parents and relatives are affected by the disease from severe mental health problems and moods. Due to the disease itself, the patients suffer from a severely weakened musculature.

This weakening takes place throughout the body, so that internal organs and also the heart are weakened. Finally, it comes to a heart death. Likewise, ordinary activities are difficult for the person concerned to perform and patients suffer from very low exercise capacity. Not infrequently, the patients are then dependent on the help of other people in everyday life.

Joints and muscles are often deformed and there is considerable restriction of movement due to the Duchenne muscular dystrophy. Likewise, this disease can also lead to mental discomfort and thus significantly reduce the quality of life of the patient. Treatment of Duchenne muscular dystrophy is not possible.

Those affected depend on different therapies to increase life expectancy, which is greatly reduced. During treatment, however, no special complications occur.

When should you go to the doctor?

For disorders of muscle strength, decreased physical performance or muscle tension, a doctor should be consulted. If irregularities occur in the development and growth process in direct comparison to peers, a visit to a doctor is advisable. If there is low resilience or rapid fatigue, consultation with a doctor is recommended. Deformation of the body, a malposition of the upper body or a general faulty load on the skeletal system are to be examined and treated. Curvature of the spine is characteristic of Duchenne muscular dystrophy and should be discussed immediately with a physician.

In case of disturbances of the respiratory activity, a shortness of breath or interruptions of the breathing a doctor is needed. In case of an acute impairment of respiration or a lack of oxygen there is an immediate need for action. Indications for this are a blue coloring of the lips and fingers, the loss of the consciousness as well as an internal weakness. In severe cases, an emergency service is to be alerted. Until the patient arrives, he needs mouth-to-mouth resuscitation. If the person suffering from sensory or perceptual disorders of the skin, this is a sign of an existing irregularity. It should be clarified so that a treatment can alleviate the symptoms. A conspicuousness of the mental potential, an alleged mental retardation as well as a learning disability is advisable to visit a doctor.

Treatment & Therapy

To date, AMD is not curable. All attempts of gene therapy have so far been unsuccessful and probably failed due to the body's immune system. For some years, drugs are under development or even experimental testing designed to mitigate the effects of the genetic defect on dystrophin synthesis, allowing the body to synthesize dystrophin, at least to a limited extent.

One drug currently undergoing clinical trials is Eteplirsen, also referred to as AVI-4658. Another drug in the experimental phase is ataluren. In the presence of so-called nonsense mutations, which lead to a termination of the transcription of the base sequences due to so-called stop codons, ataluren should be able to prevent the termination of transcription. If successful, this means that the body would again be able to synthesize dystrophin and thereby halt muscular dystrophy.

The therapies currently used are aimed at alleviating the symptoms and also include life-prolonging measures, but do not affect the actual cause of the disease. The catalog of measures for combating symptoms consists of a mix of medical care, physiotherapy and occupational therapy as well as care and psychological support for the patients and relatives. As the disease progresses, breathing aids via oxygen masks are necessary. In later phases, a cut in the trachea (tracheotomy) is usually necessary to carry out active ventilation.

Outlook & Forecast

For Duchenne Muscular Dystrophy, healing is not possible today. The disease is characterized by a characteristic course and usually has the same prognosis for all those affected. Between the third and fifth year of age, slight muscle weakness in the legs is already noticeable. Subsequently, the disappearance of the thigh and pelvic musculature progresses steadily, with connective and fatty tissue replacing the gradually dwindling muscle tissue. Later, the muscles of the shoulders and arms are affected by muscular dystrophy.

Already between their fifth and seventh year of life, the affected children are dependent on constant help to get up from lying or sitting. Many of the affected children with Duchenne muscular dystrophy completely lose their ability to walk as early as their twelfth year, which means that they can no longer do without a wheelchair. In the further course of the disease, however, those affected can still initially, but limited supply but independently. Usually, however, patients are then dependent on full care of family members from the age of 18.

Finally, Duchenne muscle dystrophy also affects the respiratory muscles and heart muscle of those affected, reducing their life expectancy. In the process, the disease almost always leads to death by suffocation or heart failure.

prevention

Because muscular dystrophy AMD is caused by a genetic defect, direct preventive measures that could provide protection against the onset of the disease are not known. An early diagnosis, preferably still in the first or second year of life, however, helps to combat the symptoms of a wide range of therapeutic measures and delay. In addition to the nutrition and supply of the body with minerals, amino acids, vitamins, enzymes and trace elements, a targeted physiotherapy is important to maintain the muscle functions as long as possible.

aftercare

In Duchenne muscular dystrophy, the possibilities of direct follow-up are usually significantly reduced or in some cases even not available to the patient. For this reason, the person concerned should ideally seek medical attention at an early stage to prevent the onset of other symptoms or complications.

It can not come to a self-healing, so a visit to a doctor is usually necessary. Most patients are dependent on the help and care of their own family in everyday life. In doing so, those affected must be relieved of stress, generally avoiding efforts or stressful and physical activities.

Often, psychological support is also important to prevent the onset of depression and other mental disorders. Furthermore, in Duchenne muscular dystrophy, physiotherapy is necessary to alleviate and reduce discomfort. Many of the exercises can also be repeated in one's own home in order to additionally relieve the symptoms.

Further measures of follow-up care are usually not available to the person concerned with this disease. Duchenne muscular dystrophy may also reduce the patient's life expectancy.

You can do that yourself

If you live with Duchenne Muscular Dystrophy, remedies are very important to you. They increase the quality of life, make everyday life easier and support participation in society. It is therefore all the more important to know well what aids are in question and which options of care there are. In the late walk-in phase and the ineligible phase, additional aids may be required to cope with everyday situations such as eating and drinking as well as personal hygiene.

To obtain information, aid fairs are an excellent opportunity for manufacturers to present their products. There you get a good overview, which aids come into question. In addition, contact with other families affected by Duchenne muscular dystrophy or other muscle disorders may also be helpful. The German Society of Muscular Diseases offers a comprehensive counseling service and supports parents to establish contact with other victims.

If the affected child does not have to rely on the wheelchair for a long time, wheelchair training at the beginning can be helpful in learning how to use the wheelchair correctly.

The flexibility of the muscles and the maintenance of the joint mobility are important prerequisites for maintaining limb function as long as possible. In many cases, daily stretching exercises with family support are essential in addition to physiotherapy.

Tags: 
  • Diseases 
  • symptoms 
  • news 
  • babies and toddlers 
  • Food 
  • Top