Painful duchenne. Duchenne-Becker muscular dystrophy. Damage to the heart muscle

Only 1/4 of patients have the so-called preclinical stage of the disease, which manifests itself only by biochemical and histological signs. These children get sick at a later age (5-7 years old), in early childhood they are quite mobile. Much more often (in 75% of patients), manifestations of muscle weakness can be noticed by the end of the 1st - the beginning of the 2nd year of life due to insufficient motor activity of the child, difficulty getting up from the floor, squatting, and late start of walking. In this stage of the disease, there is relative compensation - there is no visible progression of the disease, even, on the contrary, due to natural development, the child becomes more mobile over time. The symptoms of the disease are not yet specific enough, but the features of the weakness of the muscles of the pelvic girdle are evident.

Children with Duchenne disease begin to walk later than their peers, when walking awkwardly, with difficulty climbing stairs. Often, observant parents already in this period go to the doctor, but their complaints do not receive due attention. The delay in walking is explained by "rickets", "flat feet", excessive fatness of the child or general weakening after an illness. The gradual accumulation of dystrophic changes in the muscles by the 3-5th year leads to the identification of typical movement disorders, a clear progression of the disease begins, which goes through a number of stages.

In the initial stage, all symptoms are expressed implicitly, but quite clearly. Children still retain some liveliness of movements, but they cannot withstand the load. When walking for a long distance, you can notice a violation of posture as a result of lumbar hyperlordosis, a slightly waddling gait or a slight protrusion of the abdomen forward, thick calves. The child has difficulty climbing stairs, getting up from the floor, squatting. Frequent falls of the child while walking encourage parents to see a doctor.

The stage of pronounced manifestations, the disease, or the stage of generalization of atrophy, occurs rather quickly, in some cases after a few

months after the visible onset of progression of muscle weakness. The lumbar lordosis gradually increases, the gait becomes "duck", the feet are deformed. At this stage, there is a characteristic gradual getting up from the floor due to muscle weakness. In the future, the patient cannot get up on his own. When walking, the abdomen protrudes sharply forward, the upper body deviates backward. From time to time the strength leaves the patient, and he, as if knocked down, can collapse to the floor and cannot stand up for a long time. This condition portends an imminent loss of walking.

The severe paralytic stage of the disease is characterized by the impossibility of independent movement and occurs, as a rule, at 10-11 years old, although the duration of the disease before the loss of walking can vary significantly (from 2 to 10 years, and in exceptional cases up to 12-13 years). This is explained not only by the severity of the disease, but to a greater extent by the extreme sensitivity of the myo-dystrophic process to external influences. Sometimes it is enough for the sick person to spend a few days in bed because of the flu to get them back on their feet. Such a premature loss of walking is observed after the application of plaster, with a rapid increase in body weight by 3-4 kg or more, after changes in physical activity (long walking). Thus, for dystrophic muscles, inaction is just as destructive as overload.

It has been noticed that with the loss of the ability to move independently, muscle atrophy and weakness grow very quickly. The patient soon loses the ability to sit up in bed with the help of his hands and roll over on the other side. Contractures develop rapidly.

After several years of sitting in a chair, gross deformations of the skeleton are noticeable. By the age of 14-16, the immobility of patients reaches an extreme degree. They usually die before the age of 20, rarely later * - in a state of deep general dystrophy, from diseases of the lungs, liver, heart, etc.

An increase in the volume of the calf muscles is a constant and characteristic symptom of Duchenne disease, called pseudohypertrophic. Biopsy shows calf enlargement rarely depends on true hypertrophy

Chapter XI. Psychological characteristics of children with myopathy

§ 2. Clinical features of Duchenne myopathy

Muscle fibers, and in most cases occurs due to an increase in connective and adipose tissue. Hence the name pseudohypertrophy.

In Duchenne myopathy, pseudohypertrophies are usually detected after the child has already begun to walk on his own. Up to 2-2.5 years old, pseudohypertrophy does not look demonstrative due to the natural structural features of the child's body, but with comparative palpation, an increased density of the calf muscles can be found compared to the femoral muscles. In a severe stage, pseudohypertrophy is often difficult to detect. Previously hypertrophied muscles gradually decrease in volume and in appearance differ little from atrophied ones.

The decrease in tendon reflexes goes parallel to the degree of dystrophic process in the muscles, knee reflexes usually fall out first. In most cases, the disappearance of knee reflexes is ahead of the development of visible atrophy of the quadriceps femoris muscles. Then tendon reflexes of the hands go down and fall out.

Muscle weakness and atrophy in the myodystrophic process develop in parallel. However, atrophy in the muscles of the pelvic girdle and thighs in the initial and mild stages of the disease are invisible, while weakness is clearly detected. Atrophies become noticeable earlier in the muscles of the shoulder girdle.

Often in the early stages of the disease there are complaints of pain in the legs, mainly in the feet, popliteal fossa and groin folds. Pain occurs when walking and disappears in the belt. Children often ask for hands. Sometimes there are rare pains in the calf muscles. In all likelihood, pain is caused by compensatory overload of relatively intact muscles and ligaments, as well as microcirculatory disorders.

The proliferation of connective tissue in the muscles leads to their shortening. Tendons and ligaments are also subjected to this process, which leads to limited mobility in the joints, contractures. Thus, contractures in muscular dystrophy are a consequence of

changes in the muscle itself. Earlier than others, shortening of the calf muscles and Achilles tendons with limited dorsiflexion of the foot usually occurs. The patient begins to walk on tiptoes. The shape of the feet gradually changes. Feet with a high arch are observed in about 1/4 of patients, flat feet are somewhat less common. In the paralytic stage of the disease, the high arch, combined with a fixed position, forms the so-called equine foot.

Deformation of the chest can be noticed quite early in patients. Most often, the chest is flattened in the anteroposterior direction. If at the same time there is a depression of the sternum, the rib cage acquires a scaphoid shape. A barrel chest is less common than a flattened one.

Bone changes, narrowing of the diaphysis of large tubular bones. In all cases, osteoporosis is found. These changes are quite pronounced already at that stage of the disease, when good mobility of the patient is still preserved, therefore they can hardly be attributed to secondary atrophic processes in the bones from inaction. In patients with Duchenne myopathy, a delay in ossification is determined radiographically.

With Duchenne myopathy, endocrine disorders are not uncommon - excessive weight loss, reaching in some cases a degree of cachexia, or, conversely, unusual fullness. In Duchenne myopathy, obesity is usually accompanied by features of congenital hypogenitalism (cryptorchidism, small size of the penis and scrotum).

The almost uniform deposition of fat is somewhat more pronounced on the abdomen, in the pelvis, chest, arms, and face. The patient retains a childish body shape.

Mental insufficiency of patients with a pseudohypertrophic form was noted by Duchenne, but until now there is no consensus on this issue. Mental retardation is observed in about a third of patients. For patients with Duchenne myopathy, lethargy, slowness of thinking are characteristic. This can be complemented by poor memory and impaired attention, inability to concentrate. The listed features make

Chapter XI. Psychological characteristics of children with myopathy ______

sick children are extremely inert both at school and among their peers. Their speech is poor. Due to the slowing down of mental activity, they do not use the available vocabulary in speech, prefer to speak in the simplest phrases, sometimes sit in silence for hours. In many cases, it is not possible to identify the experiences associated with their own difficult situation, immobilization.

Along with muscle disorders, internal organs suffer. Functional weakness of the myocardial muscles reduces its ability to decompensate and in adulthood can lead to acute heart failure with a poor prognosis. Weakening of the muscles involved in the act of breathing often causes congestion in the broncho-pulmonary apparatus, which leads to acute respiratory diseases. The latter can be aggravated by the development of pneumonia. A decrease in the peristaltic capacity of the gastrointestinal tract disrupts digestion.

At all stages of the development of the pathological process, it is very important prevention of fractures at home. Falling sick boys with unstable walking leads to limb fractures. This fact is explained by pathological changes in the bone tissue, which becomes fragile in the course of the disease. Healing of fractures occurs at the usual time, but plastering the limbs leads to immobility, after which such a child sometimes loses the ability to move without anyone's help.

Although the gene for the disease is known, there is still no effective treatment for the disease. However, intensive development of genetic treatments is currently underway.

Duchenne muscular dystrophy (myopathy) is considered an extremely severe hereditary disease with a progressive course, which is characterized by primary muscle damage. This disease has been known since the middle of the nineteenth century, when the neurologist Guillaume Duchenne conducted a comprehensive analysis of muscle pathology and presented it to the scientific community. There are several variants of the course of the disease, which are separated into separate nosological forms.

Duchenne myopathy is recorded in one infant out of 4 thousand newborns. Among all classified muscular dystrophies, this form is considered the most common.

Causes

The disease is associated with a mutation in the DMD gene, which is responsible for the production of the dystrophin protein. This gene is located on the X chromosome. The main function of the dystrophin protein is to ensure the structural stability of a specific glycoprotein complex that is located on the basement membrane of the muscle cell. As a rule, the male sex suffers from Duchenne myopathy. At the same time, women can be carriers of the disease.

Clinical picture

Duchenne myopathy begins to appear in boys under 5 years of age. The child is rapidly fatigued. He often falls, it is quite difficult for him to climb even stairs. What clinical symptoms will be typical:

Progressive weakness in the legs.
"Duck" gait. When walking, he tries to lean on the forefoot.
Over time, muscle weakness spreads to the upper limbs, neck, torso.
Pseudohypertrophy is revealed. The calf and deltoid muscles are increased in size due to adipose and connective tissue.
Low stamina.
Contractures (limitation of mobility) in the joints of the arms and legs.
It's hard to stand without help.
With great difficulty he gets out of bed.
At the age of 8–10, they can no longer walk on their own.
Pronounced curvature of the spinal column.
Progressive muscular dystrophy leads to the development of paralysis.
From about 12 years of age, almost all patients cannot do without a wheelchair.

Myocardial damage is noted quite early. Children complain of shortness of breath and the appearance of painful sensations in the region of the heart. Usually death is associated with severe problems with the respiratory system and heart. The average life expectancy of patients varies from 20 to 30 years. There are isolated cases when people with muscular dystrophy lived to be 40 years old.

In most patients, serious mental abnormalities are not found, but it all depends on individual characteristics and hereditary predisposition.

Diagnostics

The characteristic clinical picture provides strong grounds for suspecting muscular dystrophy. Laboratory and instrumental diagnosis of the disease consists of the following methods:

DNA test.
Electromyography.
Muscle fiber biopsy.
Prenatal diagnostics.

Thanks to the latest technology, genetic testing can be carried out to detect mutations. In the overwhelming majority of cases, molecular genetic analysis confirms the results of other diagnostic methods. Electromyography makes it possible to assess the state of skeletal muscles and conclude that weakness is caused by damage to muscle fibers, and not by impaired nerve conduction.

If genetic testing does not reveal mutations, then a muscle fiber biopsy may be considered. In the process of this manipulation, a very small tissue sample is taken and a histological examination is performed. If the protein dystrophin is not detected in muscle tissue, it can be argued with a fairly high probability that the patient has Duchenne muscular dystrophy. It should be noted that modern DNA tests have become more accurate, and muscle fiber biopsy is used less and less.

In the case when the mother and father are carriers of a mutational gene, the risk of having a child with this hereditary pathology is very high. Whether there is a hereditary defect in the fetus - this can be determined using prenatal diagnostic methods:

Chorionic biopsy is done at 11-14 weeks.
Amniocentesis is acceptable after 15 weeks.
It is possible to take blood from the fetus at 18 weeks.

When choosing one or another method of prenatal diagnosis, one should be guided by the recommendations of a geneticist. Conducting special studies in the early stages of bearing a fetus allows you to terminate a pregnancy in a timely manner in the event of a hereditary pathology. At the same time, using these diagnostic methods, the risk of miscarriage in the future increases.

The leading clinical symptom of Duchenne myopathy is progressive muscle weakness due to atrophic changes in the muscles.

Treatment

Unfortunately, to date, there is no effective treatment that will help rid the patient of hereditary Duchenne myopathy, as well as from. Considering the results of recent clinical studies, great hopes are pinned on the use of stem cells, which will have to replace abnormal muscle fibers. Nevertheless, the treatment is now symptomatic, and its main task is to try to improve the patient's quality of life. What medical methods are used:

Symptomatic drug therapy.
Respiratory function support.
Use of various orthopedic aids (fixing belts, etc.).
Physiotherapy procedures.
Massage.
Physiotherapy.

Despite all the efforts of modern medicine, Duchenne myopathy remains an incurable disease.

Symptomatic therapy

When using drug treatment, there is a positive trend in the course of hereditary Duchenne muscular dystrophy.

quite often used (Prednisolone, Deflazacort), which help to slow down the pathological process in muscle fibers. A therapeutic course with steroid drugs helps to increase muscle strength and reduce the severity of some clinical symptoms. However, the effect of their use persists for a short time and the risk of adverse reactions is high.

In addition, clinical studies have been conducted on the use of drugs from the beta-2-agonist group. In patients with Duchenne myopathy, they increased muscle strength but did not slow the progression of the disease. Dynamic control was carried out throughout the year. Therefore, it is difficult to talk about the long-term effect of using this group of drugs for the treatment of hereditary pathology.

Breathing support

The progression of the disease inevitably leads to serious breathing problems, as well as with. The need to use artificial ventilation is determined by the level of oxygen saturation in the blood. Currently, there is a wide selection of various portable devices that allow you to do this at home. As a rule, artificial ventilation of the lungs is already required during adolescence. But there are times when, even at the age of 20, patients do not need respiratory support.

If the breathing mask does not provide sufficient oxygenation of the blood, the following may be performed:

Intubation (insertion of a special tube into the trachea through the nose or mouth).
Tracheostomy operation (insertion of a tube through a tracheal incision on the front of the neck).

The duration of the use of artificial ventilation depends on the functioning of the respiratory system. If the vital capacity of the lungs falls below 30% of normal values, you should constantly use such devices. Modern types of transport artificial ventilation devices are quite compact and easy to use.

By the level of creatine phosphokinase in the blood, one can judge the degree of development and progression of Duchenne muscular dystrophy.

Stem cell therapy

Clinical research is underway to develop an effective treatment for hereditary myopathy. One of the promising areas is the use of stem cells. Scientists believe that under certain conditions these cells will be able to replace damaged muscle fibers.

In addition, gene therapy is no less promising. For example, activation of the gene responsible for the production of utrophin is of considerable interest for the treatment of hereditary Duchenne muscular dystrophy. As it turned out, this protein is, in fact, considered an analogue of dystrophin. By activating the production of utrophin, it will be possible to partially compensate for the lack of dystrophin in muscle fibers.

Physiotherapy

Each patient with Duchenne myopathy is shown physiotherapy exercises, the purpose of which is to prevent and slow down the development of contractures (limitation of mobility in the joints), as well as to improve muscle tone and strength. It is necessary to start doing exercise therapy as early as possible, immediately after the first signs of pathology appear. The level of physical activity and the set of exercises are determined individually, taking into account the severity of the disease and the general condition of the patient.

There are separate rehabilitation centers where they purposefully deal with people with this kind of disabilities. On average, 3-4 courses of exercise therapy are completed per year. In the intervals between planned physiotherapy courses, it is recommended to do physical therapy independently at home. Most parents, after preliminary instruction with a specialist, cope with this task quite well.

If the patient's condition allows and there is an opportunity, you can visit the pool. Swimming and exercise in water have a very beneficial effect on the body of a child suffering from such a serious illness. Many experts believe that in the absence of contraindications, training in the pool should be recommended to every patient with hereditary muscular dystrophy.

Lack of moderate physical activity contributes to the progression of Duchenne myopathy.

Massage

In the treatment of muscular dystrophy, special massage techniques are used. Improving muscle tone is the main task of a massage therapist. It is recommended to systematically and regularly undergo therapeutic courses. In most cases, doctors try to teach relatives about standard techniques so that at the same time they can independently perform massage at home. The positive effect is observed in patients whose treatment included a combination of physical therapy, physiotherapy procedures and massage sessions.

Physiotherapy

Complex symptomatic treatment of Duchenne myopathy almost always includes physiotherapy procedures. What effect can be expected from the use of these therapeutic methods:

Activation of metabolic processes and improvement of trophism in muscle tissue.
Suppression of dystrophic changes in muscles.
Normalization of peripheral blood circulation and microcirculation.
Improving neuromuscular conduction.

Patients with muscular dystrophy may be prescribed the following physical treatments:

Electrophoresis.
Laser therapy.
Hydromassage.
Balneotherapy.
Infrared irradiation.
Phonophoresis.

Forecast

In Duchenne myopathy, the pathological process extends to all types of muscles: skeletal muscles, myocardium, bronchial smooth muscles, etc. Usually, the average life expectancy does not exceed 30 years. In isolated cases, patients with hereditary muscular dystrophy can survive to the age of 40. Correct organization of patient care and the use of all modern means that can alleviate his condition can increase life expectancy.

The main method of disease prevention is prenatal diagnosis. Having identified a serious hereditary pathology in the early stages of bearing a fetus, you can make a timely termination of pregnancy.

There are a huge number of different diseases that occur in children, regardless of circumstances or environmental influences. This is a category of hereditary diseases. Now we will talk about such a problem as Duchenne muscular dystrophy: what kind of ailment it is, what are its symptoms and whether it is possible to cope with it.

Terminology

Initially, you need to find out what it is. So, these are diseases that arise as a result of defects in the apparatus of hereditary cells. That is, these are certain failures that occur at the genetic level.

Duchenne muscular dystrophy is precisely a hereditary disease. It manifests itself very quickly, the main symptom in this case is rapidly progressive muscle weakness. It should be noted: like all other muscular Duchenne also leads in the end result to impaired motor skills and, of course, disability. In adolescence, children with such a diagnosis no longer have the opportunity to move independently and cannot do without outside help.

What Happens at the Genetic Level

As already noted, Duchenne muscular dystrophy is so, a mutation occurs in the gene that is responsible for the production of a special protein called dystrophin. It is he who is necessary for the normal functioning of muscle fibers. It is important to note that this genetic mutation can both be inherited and occur spontaneously.

It is also important to note that the gene is localized on the X chromosome. But women cannot get this disease, being only a transmitter of the mutation from generation to generation. That is, if a mother passes the mutation on to her son, he will get sick with a 50% probability. If the girl will simply be a carrier of the gene, she will not have clinical manifestations of the disease.

Symptoms: groups

Basically, the disease actively manifests itself at about 5-6 years of age. However, the first symptoms may occur in a baby who has not yet reached the age of three. It should be noted that all pathological disorders of honey are conventionally divided into several large groups:

The defeat of the musculature.
Damage to the heart muscle.
Deformation of the child's skeleton.
Various endocrine disorders.
Disorders of normal mental activity.

The most common manifestations of the disease

Be sure to also talk about how Duchenne syndrome manifests itself. Symptoms are as follows:

Weakness. Which gradually grows and develops.
It starts progressing with the upper extremities, then the legs are affected, and only then - all other parts of the body and organs.
The child loses the ability to move around on his own. By about the age of 12, such children are already completely dependent on a wheelchair.
Respiratory system disorders are also observed.
And, of course, there are violations in the work of the cardiological system. Later, irreversible changes occur in the myocardium.

About damage to the muscles of the skeleton

It is lesions of muscle tissue that are the most common symptom when it comes to a problem such as Duchenne's syndrome. It should be noted that babies are born without any special developmental deviations. At a young age, children are less active and mobile than their peers. But most often this is associated with the temperament and character of the child. Therefore, deviations are very rarely noticed. More significant signs appear already while the baby is walking. Such children can move on their toes without standing on their full feet. They also often fall.

When the boy can already speak, he constantly complains of weakness, pain in the limbs, and rapid fatigue. Such crumbs do not like to run, jump. They do not like any physical activity, and they try to avoid it. "To say" that the baby has Duchenne muscular dystrophy can even walk. She becomes like a duck. The boys seem to waddle from foot to foot.

The Govers symptom is also a special indicator. That is, a child, to get up from the floor, actively uses his hands, as if climbing on his own.

It should also be noted that with such a problem as Duchenne's syndrome, the child's muscles gradually atrophy. But it often happens that the crumbs outwardly have muscles that seem very developed. The boy even at the first jump turns out to be pumped up, as it were. But this is just an optical illusion. The thing is that in the process of illness, muscle fibers gradually disintegrate, and their place is taken by adipose tissue. Hence such an impressive appearance.

A little about the deformation of the skeleton

If the child has progressive Duchenne muscular dystrophy, then the boy's skeleton will gradually change. First, the pathology will affect the lumbar spine, then scoliosis will occur, that is, the curvature of the thoracic spine will occur. Later, the stoop will appear and, of course, the normal shape of the foot will change. All of these symptoms will furthermore accompany the deterioration of the baby's motor activity.

About the heart muscle

A mandatory symptom in this disease is also damage to the heart muscle. There is a violation of the rhythm of the heart, there are regular drops in blood pressure. In this case, the heart increases in size. But its functionality, on the contrary, is diminishing. And as a result, heart failure is gradually formed. If this problem is still combined with respiratory failure, then there is a high probability of death.

Mental disorders

It should be noted that Duchenne-Becker muscular dystrophy is not always manifested by such a symptom, as This may be due to a deficiency of a substance such as apodystrophin, which is necessary for the functioning of the brain. Intellectual disabilities can be very different - from weak mental retardation to idiocy. The inability to attend kindergartens, schools, clubs and other places where children congregate also contributes to the aggravation of these cognitive disorders. As a result, social maladjustment occurs.

Disorders of the endocrine system

Various endocrine disorders occur in no more than 30-50% of all patients. Most often it is just overweight, obesity. At the same time, children also have a lower height than their peers.

Outcome of the disease

What is the clinical and epidemiological characteristics of Duchenne muscular dystrophy? Thus, the incidence of the disease is 3.3 patients per 100 thousand healthy people. It should be noted that muscular atrophy is gradually progressing, and by the age of 15, the boy can no longer do without the help of others, being completely immobilized. In addition, there is also a frequent attachment of various bacterial infections (most often it is the genitourinary and respiratory systems), with improper child care, bedsores appear. If problems with the respiratory system are combined with heart failure, this can be fatal. Generally speaking, such patients almost never live more than 30 years.

Diagnosis of the disease

What procedures can help identify with the diagnosis of Duchenne muscular dystrophy?

Genetic testing, that is, DNA analysis.
Electromyography, when a primary muscle change is confirmed.
Muscle biopsy, when the presence of the protein dystrophin in the muscle is determined.
A blood test to determine the level of creatine kinase. It should be noted that it is this enzyme that indicates the death of muscle fibers.

Treatment

It is impossible to completely recover from this disease. You can only alleviate the manifestation of symptoms, which will make the patient's life a little easier and more convenient. So, after the patient is diagnosed with this, most often he is prescribed therapy with glucocorticosteroids, which are designed to slow down the development of the disease. Other procedures that can also be used for this problem:

Additional ventilation of the lungs.
Medication therapy, which is aimed at normalizing the work of the heart muscle.
The use of various devices that increase patient mobility.

It is also important to note that the development of the latest techniques based on stem cell transplantation is underway.

Other muscle diseases

There are also other congenital muscle diseases in children. Such diseases include, in addition to Duchenne dystrophy:

Becker's dystrophy. This disease is very similar to Duchenne syndrome.
Dreyfus muscular dystrophy. It is a slowly progressive disease in which intelligence is retained.
Erb-Roth progressive muscular dystrophy. It manifests itself in adolescence, the progression is rapid, disability occurs early.
Shoulder-facial form of Landouzi-Dejerine, when muscle weakness is localized in the area of the face, shoulders.

It should be noted that none of these diseases manifest muscle weakness in newborns. All symptoms occur mainly during adolescence. The life expectancy of patients most often does not exceed 30 years.

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Congenital muscle weakness, which progresses with the development of the body, is called Duchenne muscular dystrophy in medicine. This disease affects only boys and has severe symptoms. The importance of understanding the nature of the disease can alleviate the signs of pathology and help children cope with such a problem.

Characteristics of pathology

Duchenne syndrome is characterized as a genetically determined disease, expressed by a change in the structure of muscle fibers. Duchenne muscle myopathy is associated with damage to the structure of the gene responsible for the production of the muscle protein dystrophin. Duchenne muscular dystrophy is inherited and manifests itself through the generation. Due to the fact that this type of Duchenne muscular dystrophy is linked to the X chromosome, the pathology mainly affects boys.

The disease destroys the structure of the muscle, and the fiber breaks down, as a result of which the ability to move is lost. Often this pathology leads to a fatal outcome. In addition to damage to the muscular system, manifestations of the disease lead to deformation of the skeleton, heart failure, and disruption of the functioning of the endocrine system.

The cause of the appearance of Duchenne muscular dystrophy is expressed in a defect in the sex X chromosome. This disrupts the production of dystrophin, which is responsible for maintaining the cell base, the ability of muscle fibers to contract and relax. In the absence of this cementing element of the cell, the muscle base begins to degenerate and be replaced by adipose and connective tissues. All these factors lead to the loss of the ability to move.

Duchenne syndrome is transmitted by a recessive type that is linked to the X chromosome. This fact suggests that pathology develops in one or similar areas of two chromosomes. If one of the chromosomes is healthy, then the disease will not manifest. For this reason, Duchenne muscular dystrophy is the lot of men who have one X chromosome and two paired Y chromosomes. Having inherited a damaged chromosome, the boy also gets the disease, since he does not have another healthy chromosome. Women are carriers of this pathology, which they then pass on to their children.

Duchenne myodystrophy affects the neuromuscular system. The manifestation of the disease can be observed at the age of two to three years. Parents notice that the child begins to lag behind in physical development, muscle weakness appears. Duchenne myodystrophy begins to progress, affecting the legs. Further, the disease spreads to other areas of the muscles. Degenerative processes involve the upper shoulder girdle, quadriceps muscle of the thigh.

Damage to the muscle corset and stress lead to curvature of the limbs. In addition to these complications, patients have changes in the work of the heart and a delay in intellectual development.

At the age of five, the child begins to develop pseudohypertrophy of the calves. Duchenne's syndrome progresses and leaves traces of its impact on the child's body with the appearance of a pterygoid scapula and a narrow waist. The child gets tired quickly with minimal exertion.

By the age of ten, Duchenne myopathy develops rapidly, the child turns into a disabled person. The danger of this disease lies in the processes that accompany the course of the disease. Under the influence of pathology, internal organs suffer, pneumonia, heart failure are characteristic.

Related manifestations of pathology

Myopathy is a collective term that includes several genetic diseases, and is accompanied by degenerative processes in the muscles. Myopathies have primary and secondary manifestations. The first two groups include spinal amyotrophies, which affect the anterior horns of the spinal cord, and neural. The latter change the peripheral nerve trunks. These two types are the primary form of myopathy.

With severe infections and against the background of endocrine disorders, secondary amyotrophy occurs.

Amyotrophy is defined as a hereditary degenerative change in the muscular system with its atrophy and impaired contractile function due to damage to the peripheral motor neuron. Among the spinal forms, diseases of Werdnig-Hoffmann, Kugelberg-Welander, Aran-Duchenne are distinguished.

The first form of pathology develops in utero. The fetal movement is manifested sluggishly, after the birth of the child, doctors observe the absence of movement, muscle atrophy. Kugelberg-Welander amyotrophy develops at the age of three to six years. Weakness of the muscular system begins to manifest itself in the pelvic region, gradually rising through the body.

At forty, Aran-Duchenne amyotrophy can be observed. The syndrome has its own characteristic manifestations. A person develops a symptom of a monkey's hand, muscle atrophy occurs symmetrically, rising to the pharynx and larynx. At a later stage, amyotrophy affects the legs, reflexes are reduced.

Duchenne syndrome and its symptoms

Symptoms of the disease are determined based on the nature of the changes. They are divided into groups:

deformation of the skeleton;
muscle breakdown;
changes in the work of the heart;
deterioration in mental development;
endocrine system disorder.

The characteristic symptoms of pathology begin to manifest themselves in walking. Children fall and try to move on their toes. When the disease progresses, the child begins to feel weak, he loses interest in swimming, running. Dystrophy is expressed by rapid fatigue from exertion.

Duchenne syndrome is characterized by the appearance of a "duck" gait in children. Symptoms of the disease are expressed in the fact that the child stands up "ladder". This method helps him to rise to weak legs.

At the initial stage of the development of pathology, a decrease in tendon reflexes is observed. Further, the symptoms of the disease appear in the curvature of the foot, the chest acquires a keeled shape. In addition, by listening to the heart, doctors observe changes in the rhythm of the heartbeat.

Dangerous symptoms of the disease are manifested in mental disorders, often
signs of mental retardation begin to assert themselves.

At the last stage of the development of the disease, the symptoms become more pronounced and there is a complete loss of the ability to move. At twenty, these patients die, the death is associated with pulmonary heart disease.

Revealing

Duchenne muscular dystrophy is diagnosed both by examination and research.

Doctors order blood tests to determine the level of the enzyme creatine phosphokinase. In pathology, the level of the enzyme is quite high. This indicator reflects the degree of death of the muscle fiber.

Symptoms of the disease appear on the basis of muscle testing. According to electromyography, specialists measure the speed of a nerve impulse in the muscles of a child. In children with pathology, test results are very different from the norm.

Another method for diagnosing a disease is breathing tests, which allow you to find out the capacity of the lungs. In addition, children undergo electrocardiogram and ultrasound of the heart. The data of these examinations make it possible to establish the degree of violations of the heart muscle.

Treatment

In the case of Duchenne pathology, one cannot speak of treatment and complete healing as such. Unfortunately, no cure has yet been invented for this disease. Therefore, Duchenne muscular dystrophy is treated symptomatically.

Basically, the treatment of pathology is aimed at extending the child's period of physical activity. Therapy aims to reduce and alleviate complications from this incurable disease.

Medication treatment involves the use of steroids and beta-2-adrenergic agonists. Reception of the first group of funds makes it possible to temporarily reduce the weakness of the muscle corset. The second group of drugs gives strength to the muscles, but cannot stop the development of pathology.

The mainstay of treatment is the use of hormones that help slow the progression of the disease for a while. It is also known that taking steroids reduces the risk of developing scoliosis. Doctors recommend starting such treatment with a stable development of the disease.
Prednisolone and Deflazacort are especially popular to combat the disease. But any drug should be used strictly as directed by your doctor.

Steroids are taken as long as the clinical effect is visible, if the pathology has begun to progress, the medication should be discontinued.

In addition to hormones, with dystrophy, drugs are taken that support the work of the heart muscle. These drugs strengthen the heart against the destructive effects of pathology.

Physiotherapy has a very positive effect on the course of the disease. This method allows you to maintain flexibility of the joints, maintain muscle strength. It is also important to do massages, they increase tissue nutrition.

In addition, orthopedic devices also facilitate the patient's fate. Among them stand out and verticalizers, which help to maintain the "standing" position, and devices for independent movement.

Muscular dystrophy is also treated by exon skipping. This procedure can slow the rate at which myopathy spreads. This method reduces symptoms, but is not able to stop the mutation.

Some specialists treat the disease with myogenic cell transplant and the introduction of the dystrophin gene. These methods have a positive clinical effect.
Children remain mobile for a long time. Also, doctors are trying to restore muscle fibers using stem cells, which improve muscle function.

In addition, the treatment of the disease is carried out by blocking myostatin. This method promotes the growth of muscle tissue.

When the disease affects the pulmonary system, doctors prescribe the use of ventilators. These remedies can alleviate the difficulties that arise as the disease progresses.

Physicians, scientists through research and experiments are trying to find a miracle cure for this scourge. New developments are advancing medicine in this direction, but so far the elixir for the disease has not been invented.

Etiology and incidence of Duchenne muscular dystrophy... Duchenne muscular dystrophy (MIM # 310200) is a pan-ethnic X-linked progressive myopathy caused by mutations in the DMD gene. The incidence is approximately 1 in 3500 male newborns.

The pathogenesis of Duchenne muscular dystrophy... The DMD gene encodes dystrophies, an intracellular protein expressed predominantly in smooth, skeletal and cardiac muscle, as well as in some neurons in the brain. In skeletal musculature, dystrophy forms part of a large complex of sarcolemma-associated proteins that provide sarcolemma stability.

Mutations in gene DMD that cause Duchenne muscular dystrophy include large deletions (60-65%), large duplications (5-10%), and small deletions, insertions or substitutions of nucleotides (25-30%). The largest deletions occur in one of two hotspots. Nucleotide substitutions occur throughout the gene, predominantly in CpG dinucleotides.

De novo mutations occur with a comparable frequency during ovogenesis and spermatogenesis; the largest de novo deletions occur during ovogenesis, while most de novo nucleotide substitutions occur during spermatogenesis.

Mutations, causing the phenotypic absence of dystrophin, lead to more severe muscle damage than mutant DMD alleles expressing partially functional dystrophies. No correlation was found between genotype and phenotype for intellectual decline.

Phenotype and development of Duchenne muscular dystrophy

Men with Duchenne muscular dystrophy... Myodystrophy is a progressive myopathy resulting in muscle degeneration and weakness. Starting in the muscles of the hip girdle and flexors of the neck, muscle weakness progressively affects the shoulder girdle and distal muscles of the limbs and trunk. Although occasionally, patients are accidentally diagnosed during the neonatal period due to hypotension or developmental delay, usually sick boys are diagnosed at the age of 3 to 5 years with the appearance of gait anomalies.

By the age of 5, most affected children use Govers' techniques and have pseudohypertrophy of the lower leg muscles, i.e. an increase in the legs due to the replacement of muscles with adipose and connective tissue. By the age of 12, the majority of patients are immobilized in a wheelchair and have contractures and scoliosis. Most patients die from impaired pulmonary function and pneumonia; the average age of death is 18 years.

Almost 95% of patients Duchenne muscular dystrophy have certain cardiac abnormalities (dilated cardiomyopathy or electrocardiographic abnormalities), and 84% have visible lesions of the heart muscle at autopsy. Chronic heart disease occurs in almost 50% of patients, occasionally heart failure causes them complaints. Although dystrophy is also present in smooth muscle, smooth muscle complications are rare and include gastric dilatation, volvulus, and bladder hypotension.

Sick Duchenne muscular dystrophy have IQs about 1 standard deviation lower than normal, and almost a third have some degree of mental retardation. The reasons for this have not been established.

Women with Duchenne muscular dystrophy

Age of onset and severity Duchenne muscular dystrophy in women depend on the degree of displacement of the X-chromosome inactivation. If the X chromosome carrying the mutant DMD allele is active in most cells, the woman will develop signs of Duchenne muscular dystrophy; if the X chromosome carrying the normal DMD allele is predominantly active, women have only few or no symptoms of the disease.

Whether they have clinical symptoms skeletal muscle weakness, female carriers have abnormalities in cardiac muscle function, such as dilated cardiomyopathy, left ventricular dilatation, and electrocardiographic changes.

Features of phenotypic manifestations of Duchenne dystrophy:
Age of onset: childhood
Muscle weakness
Leg hypertrophy
Minor intellectual disability
High serum creatine kinase

Duchenne muscular dystrophy treatment

Duchenne muscular dystrophy diagnosis based on family history and DNA analysis or muscle biopsy with immunohistochemistry for dystrophin.

Currently cure for Duchenne muscular dystrophy not possible, although improved symptomatic treatment increased the average life span from late childhood to early adulthood. The goals of therapy are to slow the progression of disease, provide mobility, prevent or correct contractures and scoliosis, control body weight, and improve lung and heart function.

Glucocorticoid therapy can slow the progression of the disease for several years. Several experimental treatments are being investigated, including gene transfer. Most patients also need extensive counseling as they deal with the psychological effects of chronic fatal illness.

Risk of Inheriting Duchenne Muscular Dystrophy

The third part of mothers who gave birth to a single patient son are themselves carriers of mutations in the DMD gene. Nevertheless, the determination of the carriage remains a difficult task, since currently available molecular methods do not detect small mutations such as single nucleotide substitutions. Determination of the risk of carriage in families without a found deletion or duplication is based on linkage assays, a series of serum creatine casase assays, and mosaic dystrophin expression in muscle biopsy samples (due to accidental X-chromosome inactivation). The high incidence of germ cell mosaicism (approximately 14%) should be taken into account when counseling for a recurrence risk assessment.

If the mother is a carrier, everyone a son has a 50% risk of developing Duchenne muscular dystrophy, and each daughter has a 50% risk of inheriting a DMD mutation. Reflecting the random nature of X chromosome inactivation, daughters who inherit a mutation in the DMD gene have a low risk of Duchenne muscular dystrophy; however, for reasons completely incomprehensible, the risk of heart abnormalities can be as high as 50-60%. If the mother is not DNA-tested, she has an approximately 7% risk of having a boy with Duchenne muscular dystrophy due to sexual mosaicism. Genetic counseling and possibly prenatal diagnosis are indicated for these mothers.

An example of Duchenne muscular dystrophy... A.I., a 7-year-old boy, is being examined for mild developmental delay. He has difficulty climbing stairs, running, reduced strength and endurance with intense physical exertion. His parents, two brothers and a sister are completely healthy; other family members have no similar complaints. Examination revealed difficulties in jumping, Govers' techniques (a sequence of movements that facilitate getting up from the floor), weakness of the proximal muscles, waddling ("duck") gait, compaction of the Achilles tendons and markedly hypertrophied muscles of the legs. The serum creatine kinase level was 50 times higher than normal.

Insofar as anamnesis and medical examination data, including an increased level of creatine kinase, suggested myopathy, the child was referred to a neurogenetics clinic for further examination. Muscle biopsy results showed a pronounced change in the size of muscle fibers, fiber necrosis, proliferation of adipose and connective tissue, and no staining for dystrophy. Based on these results, the child was provisionally diagnosed with Duchenne muscular dystrophy and tested for a deletion in the dystrophin gene; it turned out to have a deletion from exons 45 to 48.