Duchenne muscular dystrophy. All about Duchenne myopathy: genetic factors and a complete list of symptoms Progressive Duchenne muscular dystrophy

Gene diseases is a large group of diseases that occur as a result of DNA damage at the gene level.

Duchenne muscular dystrophy (DMD) is a serious X-linked recessive disease characterized by rapid progression of muscular dystrophy, which ultimately leads to complete loss of mobility and death of the patient.

DMD usually affects only men, although women can sometimes be carriers of the disease. If the father has DMD, and the mother is a carrier, or is also sick, then the woman may develop Duchenne muscular dystrophy. The disorder is caused by a mutation in the dystrophin gene, which in humans is located on the X chromosome (Xp21).

Symptoms of the disease usually appear in male children under 5 years of age and may appear in early childhood. The first signs of the disease are progressive proximal weakness of the leg and pelvic muscles associated with loss of muscle mass. Gradually this weakness spreads to the arms, neck and other parts of the body. As the disease progresses, muscle tissue is gradually replaced by adipose and fibrous tissue. To assist with walking, special braces may be necessary at age 10, but most patients over age 12 are unable to walk without a wheelchair. Later, the following signs of the disorder appear: abnormalities in bone development, which lead to skeletal deformation, including curvature of the spine.

Diagnostics: DNA test, muscle biopsy, prenatal testing.

Treatment

There are no known effective drugs to treat Duchenne muscular dystrophy. Although, according to recent stem cell research, there are promising vectors that can replace damaged muscle tissue. However, at this stage, treatment is usually symptomatic and aimed at improving the quality of life of the sick person.

43. Basic principles of genetic counseling.

The first condition for genetic counseling is confidence that the diagnosis is correct.

Once a diagnosis has been made, genetic counseling should include:

1 - decide whether both parents should be present during the conversation (teenagers should be given the opportunity for a separate conversation);

2 - discuss the medical consequences of the defect; if relevant, it is necessary to explain the possible variability in the manifestations and course of the disease and the outcomes that can be expected in the future;

3 - analyze the genetic history of each parent and identify unrecognized genetic risk;

4 - analyze the interpretations of family members or those provided by another person;

5 - describe to the counselees the genetic basis of the disease, using visual aids (pictures demonstrating the phenotype or other signs of the disease, images of chromosomes, diagrams of types of inheritance);

6 - explain the risk of developing a genetic disease in terms that the family can understand;

7 - outline the range of possible decision choices: have children, taking into account the possible risk, do not have children, adopt the child, if possible, carry out artificial insemination (this decision is especially appropriate in all cases of autosomal recessive diseases and serious autosomal dominant diseases on the father's side ), note whether it is possible to carry out prenatal diagnosis;

8 - propose to the counselees the outcome of the discussion, and, if possible, meet with them again in order to help decide how best to proceed in this case;

9 - maintain contact with previously counseled families to provide them with information that may be useful, such as new methods for detecting parental carrier status or prenatal diagnosis.

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 last century, when 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 affects one baby out of 4 thousand newborns. Among all classified muscular dystrophies, this form is considered the most common.

Causes

The diseases are 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, which is located on the basement membrane of the muscle cell. Typically, Duchenne myopathy affects males. At the same time, women can be carriers of the disease.

Clinical picture

Duchenne myopathy begins to appear in boys before age 5. The child experiences rapid fatigue. He often falls and finds it difficult to even climb stairs. What clinical symptoms will be characteristic:

• 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, and torso.
• Pseudohypertrophy is revealed. The calf and deltoid muscles are increased in size due to fatty and connective tissue.
• Low endurance.
• Contractures (limited mobility) in the joints of the arms and legs.
• It is difficult to stand without assistance.
• With great difficulty he gets out of bed.
• At the age of 8–10 they can no longer walk independently.
• Severe 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 pain in the heart area. 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 where people with muscular dystrophy lived to be 40 years old.

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

Diagnostics

The characteristic clinical picture provides good reason to suspect muscular dystrophy. Laboratory instrumental diagnosis of the disease consists of the following methods:

1. DNA test.
2. Electromyography.
3. Muscle fiber biopsy.
4. Prenatal diagnosis.

Thanks to the latest technologies, genetic testing can be performed to identify mutations. In the vast majority of cases, molecular genetic analysis confirms the results of other diagnostic methods. Electromyography makes it possible to assess the condition of skeletal muscles and conclude that weakness is due to damage to muscle fibers, and not to a violation of nerve conduction.

If genetic testing does not reveal mutations, a muscle fiber biopsy may be performed. During this manipulation, a very small sample of tissue is taken and a histological examination is carried out. If the dystrophin protein is not detected in the muscle tissue, it can be said 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 biopsies are used less and less.

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

• Chorionic villus sampling is performed at 11–14 weeks.
• Amniocentesis is acceptable after 15 weeks.
• It is possible to take blood from the fetus at 18 weeks.

When choosing a particular method of prenatal diagnosis, you should be guided by the recommendations of a geneticist. Carrying out special studies in the early stages of gestation allows for timely termination of pregnancy if a hereditary pathology is detected. At the same time, using these diagnostic methods increases the risk of developing a miscarriage in the future.

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

Treatment

Unfortunately, today there is no effective treatment that will help relieve a patient of hereditary Duchenne myopathy, as well as from. Considering the results of recent clinical studies, great hopes are placed on the use of stem cells, which will have to replace pathological muscle fibers. However, now the treatment is symptomatic, and its main goal is to try to improve the patient’s quality of life. What treatment methods are used:

1. Drug symptomatic therapy.
2. Supports respiratory function.
3. Use of various orthopedic devices (fixing belts, etc.).
4. Physiotherapeutic procedures.
5. Massage.
6. Physiotherapy.

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

Symptomatic therapy

When using drug treatment, positive dynamics are observed during hereditary Duchenne muscular dystrophy.

Quite often used (Prednisolone, Deflazacort), which help slow down the pathological process in muscle fibers. The therapeutic course of steroid drugs helps to increase muscle strength and reduce the severity of some clinical symptoms. However, the effect of their use does not last long and the risk of adverse reactions is high.

In addition, clinical studies have been conducted on the use of drugs from the group of beta-2 agonists. In patients with Duchenne myopathy, they increased muscle strength but did not slow the progression of the disease. Dynamic monitoring 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 pathologies.

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 different portable devices that allow you to do this at home. As a rule, artificial ventilation is already required during adolescence. But there are cases when, even at 20 years old, patients do not need support for respiratory function.

If the breathing mask does not provide sufficient oxygen saturation of the blood, the following may be done:

• Intubation (insertion of a special tube into the trachea through the nose or mouth).
• Tracheostomy surgery (insertion of a tube through an incision in the trachea on the anterior surface of the neck).

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

The level of creatine phosphokinase in the blood can be used to judge the degree of development and progression of Duchenne muscular dystrophy.

Stem cell treatment

Today, clinical research is actively underway to develop effective treatment for hereditary myopathy. One of the promising areas is the use of stem cells. Scientists believe that these cells, under certain conditions, 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 indicated for physical therapy, the purpose of which is to prevent and slow the development of contractures (limited mobility in the joints), as well as improve muscle tone and strength. It is necessary to start exercising 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 specifically work with people who have this type of disorder. On average, 3–4 courses of exercise therapy are completed per year. In between scheduled physiotherapeutic courses, independent exercise therapy at home is recommended. Most parents, after preliminary instructions from 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, swimming pool exercises should be recommended to every patient with hereditary muscular dystrophy.

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

Massage

Special massage techniques are used in the treatment of muscular dystrophy. Achieving improved 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 standard techniques so that at the same time they can independently perform massage at home. A positive effect is observed in patients whose treatment included a combination of physical therapy, physiotherapeutic procedures and massage sessions.

Physiotherapy

Complex symptomatic treatment of Duchenne myopathy almost always includes physiotherapeutic procedures. What effect can you expect from using these therapeutic methods:

1. Activation of metabolic processes and improvement of trophism in muscle tissue.
2. Suppression of dystrophic changes in muscles.
3. Normalization of peripheral blood circulation and microcirculation.
4. Improvement of neuromuscular conduction.

The following physical treatments may be prescribed to patients with muscular dystrophy:

• Electrophoresis.
• Laser therapy.
• Hydromassage.
• Balneotherapy.
• Infrared irradiation.
• Ultraphonophoresis.

Forecast

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

The main method of preventing the disease is prenatal diagnosis. By identifying a serious hereditary pathology in the early stages of gestation, you can have a timely termination of pregnancy.

Etiology and incidence of Duchenne muscular dystrophy. Duchenne muscular dystrophy (MIM #310200) is a panethnic X-linked progressive myopathy caused by mutations in the DMD gene. The incidence is approximately 1 in 3,500 male births.

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

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

De novo mutations occur with comparable frequency during oogenesis and spermatogenesis; the largest de novo deletions occur during oogenesis, while the majority of de novo nucleotide substitutions occur during spermatogenesis.

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

Phenotype and development of Duchenne muscular dystrophy

Men with Duchenne muscular dystrophy. Myodystrophy is a progressive myopathy leading to muscle degeneration and weakness. Beginning with the hip girdle and neck flexors, muscle weakness progressively affects the shoulder girdle and distal muscles of the limbs and trunk. Although occasionally patients are accidentally identified during the newborn period due to hypotonia or developmental delay, usually affected boys are diagnosed between the ages of 3 and 5 years when gait abnormalities appear.

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

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

Sick Duchenne muscular dystrophy have an IQ about 1 standard deviation below 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 shift in X chromosome inactivation. If the X chromosome carrying the mutant DMD allele is active in most cells, the woman develops signs of Duchenne muscular dystrophy; If the X chromosome carrying the normal DMD allele is predominantly active, women have few or no symptoms of the disease.

Regardless of 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
Hypertrophy of the legs
Mild intellectual disability
High serum creatine kinase levels

Treatment of Duchenne muscular dystrophy

Diagnosis of Duchenne muscular dystrophy based on family history and DNA analysis or muscle biopsy with immunohistochemical determination of dystrophin.

Currently cure Duchenne muscular dystrophy impossible, although improved symptomatic treatment has increased the average life span from late childhood to early adulthood. The goals of therapy are to slow the progression of the disease, promote mobility, prevent or correct contractures and scoliosis, control body weight, and improve lung and heart function.

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

Risk of inheriting Duchenne muscular dystrophy

A third of mothers who gave birth to a single patient son, themselves are carriers of mutations in the DMD gene. However, carrier determination remains challenging because currently available molecular techniques do not detect small mutations such as single nucleotide substitutions. Determination of carrier risk in families without a found deletion or duplication is based on linkage analysis, serial serum creatine kinase levels, and mosaic dystrophin expression in muscle biopsy specimens (due to random X chromosome inactivation). When counseling to assess the risk of recurrence, the high incidence of germ cell mosaicism (approximately 14%) should be taken into account.

If the mother is a carrier, everyone son has a 50% risk of developing Duchenne muscular dystrophy, and each daughter has a 50% risk of inheriting the 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 not completely understood, the risk of cardiac abnormalities may be as high as 50-60%. If a mother is not a carrier based on DNA testing, she remains at approximately 7% risk of giving birth to a boy with Duchenne muscular dystrophy due to gender mosaicism. For these mothers, genetic counseling and possibly prenatal diagnosis are indicated.

Example of Duchenne muscular dystrophy. A.I., a 7-year-old boy, is being evaluated for mild developmental delay. He has difficulty climbing stairs, running, and decreased strength and endurance during intense physical activity. His parents, two brothers and a sister are completely healthy; other family members do not have similar complaints. Examination revealed difficulty jumping, Gowers maneuvers (a sequence of movements that make it easier to get up from the floor), weakness of the proximal muscles, a waddling (“duck”) gait, tightness of the Achilles tendons, and noticeably hypertrophied muscles of the lower legs. Serum creatine kinase levels were 50 times higher than normal.

Because the anamnesis and physical examination findings, including elevated creatine kinase levels, suggested myopathy, the child was referred to the neurogenetics clinic for further evaluation. The results of muscle biopsy showed a marked change in the size of muscle fibers, fiber necrosis, proliferation of adipose and connective tissue, and lack of dystrophy staining. Based on these results, the child was provisionally diagnosed with Duchenne muscular dystrophy and tested for deletions in the dystrophin gene; It turned out that he had a deletion from exons 45 to 48.

Duchenne muscular dystrophy (DMD)- a hereditary disease that begins at the age of 2-5 years and is characterized by progressive muscular weakness, atrophy and pseudohypertrophy proximal muscles, often accompanied by cardiomyopathies and intellectual impairment. In the early stages of the disease, increased fatigue when walking and changes in gait (“duck walk”) are observed. In this case, gradual degradation of muscle tissue occurs. 95% of patients stop walking at the age of 8-12 years. At the age of 18-20 years, patients usually die, often from respiratory failure. There is an allelic form of DMD - Becker muscular dystrophy (BMD, OMIM), which is characterized by similar clinical manifestations, a later onset (at about 10-16 years) and a milder course. Such patients often retain the ability to walk up to 20 years, and some - up to 50-60 years, although the same muscles are involved in the pathological process as in DMD. The life expectancy of such patients is reduced slightly.

A biochemical marker of the disease is an increased (100-200) times level creatine phosphokinase (KFC) in blood. In carriers of the damaged gene, the level of CPK on average is also slightly increased.

The type of inheritance of Duchenne muscular dystrophy is X-linked recessive, i.e. it affects almost exclusively boys, while women with a damaged gene on one of the X chromosomes are carriers of DMD. But in rare cases, girls can also suffer from Duchenne muscular dystrophy. The reasons for this may be the preferential inactivation of the X chromosome with a normal allele in heterozygous carriers of the mutant DMD gene, X-autosomal translocation affecting this gene, hemizygosity for the mutant allele and the presence of phenocopies (diseases associated with disruption of other proteins included in the dystrophin-glycoprotein complex ). In approximately 2/3 of cases, the son receives a damaged chromosome from the carrier mother; in other cases, the disease occurs as a result of a de novo mutation in the germ cells of the mother or father, or in the precursors of these cells. Duchenne muscular dystrophy (DMD) occurs in approximately one in 2,500 to 4,000 male births.

The DMD gene, responsible for progressive Duchenne/Becker muscular dystrophy (DMD/BMD), is located in the Xp21.2 locus and has a size of 2.6 million bp. and consists of 79 exons. In 60% of cases, mutations leading to DMD/BMD are long deletions (from one to several dozen exons), in 30% of cases - point mutations and in 10% of cases - duplications. Due to the presence of so-called deletion hot spots, amplification of the 27 exons and promoter region of the DMD gene allows detection of approximately 98% of all large deletions. The search for point mutations is difficult due to the large size of the gene and the absence of major mutations.

The Center for Molecular Genetics carries out measurements of CPK levels in the blood, as well as direct diagnosis of DMD/BMD, which is a search for large deletions/duplications in all exons of the DMD gene and a search for “point” mutations of the DMD gene using NGS (next generation sequencing). NGS research also makes it possible to detect deletions of all exons of the DMD gene in sick boys. Analysis of all exons of a gene allows us to determine the exact exon boundaries of the deletion in the case of its detection, and thus determine whether this deletion leads to a shift in the protein reading frame, which in turn is important for predicting the form of the disease - Duchenne or Becker muscular dystrophy. Thus, a combination of various research methods makes it possible to detect almost all mutations of the DMD gene.

The presence of any type of mutation (deletions/duplications in one or more exons, “point” mutations) is a molecular genetic confirmation of the clinical diagnosis of Duchenne/Becker muscular dystrophy and allows for prenatal diagnosis in a given family.

Attention! To measure CPK levels, the blood must be fresh (not frozen)!

In the case of prenatal diagnosis, fetal biomaterial is required, which can be chorionic villi (from the 8th to 12th week of pregnancy), amniotic fluid (from the 16th to 24th week of pregnancy) or umbilical cord blood (from the 22nd week of pregnancy). weeks of pregnancy).

We have developed . The kits are intended for use in molecular genetic diagnostic laboratories.

When conducting prenatal (antenatal) DNA diagnostics in relation to a specific disease, it makes sense to diagnose common aneuploidies (Down, Edwards, Shereshevsky-Turner syndrome, etc.) using existing fetal material, paragraph 54.1. The relevance of this study is due to the high total frequency of aneuploidy - about 1 in 300 newborns, and the absence of the need for repeated sampling of fetal material.

Duchenne muscular dystrophy is a rare disease. Another name for it is Duchenne muscular dystrophy or progressive Duchenne muscular dystrophy. The name is due to the fact that the disease progresses rapidly. The disease occurs in approximately 3 people out of 100,000. The pathology is caused by a congenital genetic abnormality, is severe and affects a large group of muscles. Over time, dystrophy of the muscular system leads to a complete inability to move independently.

Duchenne muscular dystrophy leads to pathology in other organs, which significantly reduces a person’s life expectancy.

The vast majority of patients with Duchenne muscular dystrophy are boys. Girls suffer from this disease extremely rarely. This is a congenital disease that is caused changes in the X chromosome. On a section of the X chromosome there is a gene that controls the production of the dystrophin protein. This protein affects the integrity of muscle fiber sheaths (sarcolemmas) and muscle resistance to stretching. It also controls calcium levels in muscle tissue and muscle growth. If a deficiency of the dystrophin protein occurs in the human body, this leads to the gradual destruction of muscle cells (myocytes). Degenerative changes occur in the muscles, muscle fibers atrophy, destroy and are replaced by fatty and connective tissue.

With progressive Duchenne muscular dystrophy, the content of normal dystrophin drops sharply due to a gene mutation. This protein is either completely absent, or the body contains defective dystrophin. In sick people, the level of normal dystrophin in the body is no more than 3%.

Girls and women very rarely suffer from this type of muscular dystrophy. But they are often carriers of an altered gene. This is due to the way the disease is transmitted through the X chromosome. As you know, the chromosome set of a man is XY, and that of a woman is XX. If a boy's mother has a defective X chromosome in her genetic makeup, then the boy may be born sick, even if the father does not have the disease.

A girl is born with Duchenne muscular dystrophy only if the mother is a carrier of the defective gene and the father suffers from this disease. Such cases are very rare. Most often, a girl born from a mother who is a carrier of a defective gene also becomes a carrier of the disease and passes it on to her sons.

However, progressive Duchenne dystrophy is not necessarily transmitted to the child from the parents. There are cases when a genetic failure occurs as a result of a random mutation. It also happens that a sick child is born to absolutely healthy parents who are not carriers of defective genes.

Symptoms of Duchenne muscular dystrophy

The disease usually manifests itself between the ages of 1 and 5 years. It affects not only the skeletal muscles, but also other organs.

1. Skeletal muscle damage is an early sign of the disease that occurs in a young child.
2. Muscle weakness progresses.
3. Due to muscle damage, the bones of the skeleton are deformed.
4. The disease affects not only the skeletal muscles, but also leads to changes in the heart. Some children with Duchenne muscular dystrophy are retarded in mental development.
5. The disease leads to disruption of the endocrine glands.

Damage to the skeletal muscles

Muscle damage is the main and early sign of the disease. Muscle symptoms become noticeable between 1 and 5 years of age.

In infancy, the child appears healthy. One can only notice that such children under the age of one year are inactive and reluctant to make any movements. Most often, parents do not attach importance to this and associate the child’s low physical activity with individual developmental characteristics.

The disease progresses; many children lose the ability to walk by the age of 12. They have to use a wheelchair.

In adolescence, the respiratory muscles are involved in the painful process. It becomes difficult for the child to breathe, and he is bothered by attacks of suffocation, especially at night. Because of this, children are afraid to sleep. This may lead to respiratory failure.

Bone lesions

Changes in the muscles lead to damage to the skeletal bones. Spinal curvatures (scoliosis, lordosis), stoop (kyphosis) occur. The chest and feet are also distorted. Bones become thinner and brittle (diffuse osteoporosis). Bone damage further limits the ability of patients to move independently.

Heart disorders

Cardiomyopathy occurs in Duchenne muscular dystrophy. The heart muscle is also involved in the pathological process. The heart increases in size, and its functions are impaired. Patients complain of arrhythmia and surges in blood pressure. Over time, heart failure may develop.

Hormonal disorders

Duchenne muscular dystrophy often leads to the development of Cushing's syndrome. Obesity occurs with fat deposits in the upper torso. Obesity is combined with insufficiency of the sex glands. Sometimes the genitals are underdeveloped. People with Duchenne muscular dystrophy are often short and overweight.

Intellectual impairment

Mental retardation is not observed in all cases. Approximately 30% of patients with Duchenne muscular dystrophy have mental retardation and low IQ. This is due to a lack of apodystrophin in the brain. A general lack of dystrophin protein in the body leads to a deficiency of its special form - apodystrophin. This substance is necessary for normal brain activity; its deficiency leads to mental impairment. The degree of mental retardation in this disease is in no way related to the severity of muscle disorders. With severe muscle weakness there may be normal intelligence.

Due to the inability to move normally, such children are often isolated from the society of their peers and cannot attend preschool and school institutions. This may worsen mental impairment.

Diagnosis of Duchenne muscular dystrophy

To diagnose myodystrophy, several types of research are used:

Treatment of Duchenne muscular dystrophy

To date, there is no radical treatment for this disease. The disease is considered incurable and progressive. It inevitably leads to disability of the patient.

Symptomatic therapy is possible to alleviate the symptoms of the disease.

Medications in the treatment of Duchenne muscular dystrophy

Physiotherapy

Physiotherapeutic methods of treatment help to temporarily preserve the patient’s motor function. Complete immobility and bed rest are contraindicated for patients; this only leads to a very rapid development of the disease. Patients need moderate activity.

• Massage and physical therapy sessions are useful.
• In order to normalize respiratory function, breathing exercises are indicated.

Orthopedic care

When motor functions are lost as a result of the disease, orthopedic devices have to be used. For muscle contractures, orthoses and special splints are used. If a serious curvature of the spine has developed, then the use of corsets helps. If it is completely impossible to move and stand independently, verticalizers and electric wheelchairs are used.

Development of new treatment methods

Even with all modern treatment methods, it is not possible to completely overcome Duchenne muscular dystrophy. The life expectancy of patients is very short. Therefore, research into new treatment methods is actively underway.

• The possibility of replacing a defective gene with a healthy gene is being studied.
• Stem cell therapy is being studied.
• Research is underway on transplanting cells capable of producing the protein dystrophin.
• Animal experiments are being conducted to replace the protein dystrophin with utrophin.
• The possibility of slowing the disease by correcting the gene (exon skipping) is being studied.

Forecast and prevention of the disease

Today, the prognosis for Duchenne muscular dystrophy is unfavorable. The disease progresses and is fatal. Most patients do not live to the age of 20-30 years. Death occurs due to cardiac and respiratory failure and associated infections.

Prenatal diagnosis plays an important role in preventing the disease. If a family already has a child with Duchenne muscular dystrophy, then in most cases this means that the mother is a carrier of a defective X chromosome. This means that there is a risk of having a sick child in subsequent pregnancies. Therefore, consultation with a geneticist and prenatal studies (amniocentesis, chorionic villus biopsy) are necessary. These methods can accurately determine whether a fetus has a genetic disease.