Limb-girdle muscular dystrophy type 2 (Duchenne muscular dystrophy, DMD) is a hereditary disease that occurs predominantly in males and is associated with progressive degeneration of muscle fibers. This rare genetic disorder occurs as a result of mutations in the DMD gene, which codes for dystrophin, a protein that ensures the integrity of muscle tissue. A lack of dystrophin leads to increased susceptibility of muscle cells to damage, which in turn leads to their replacement with fat and connective tissue. The clinical picture is manifested in muscle weakness that progresses with age, which significantly limits physical activity and reduces the quality of life of patients. The course of the disease is individual, depending on the age of onset of symptoms and the rate of their progression.
History of the disease and interesting historical facts
Limb-girdle muscular dystrophy was first described in 1861 by the British neurologist William Duchenne, whose name has become synonymous with the disease. Since then, the disease has attracted the attention of many researchers, and its genetic basis was only established in the 1980s, which was a significant step forward in understanding the pathogenesis of the disease. Establishing the function of dystrophin and its role in maintaining the structure of muscle cells confirmed the critical importance of this protein in the pathogenesis of dystrophy. Interestingly, it was Duchenne who was diagnosed with the disease, which gives his research a special symbolism in the history of medicine. In 2002, a significant number of cases were registered at the end of the 20th century, when the first genetic tests were undertaken to diagnose the disease.
Epidemiology
According to statistics, limb-girdle muscular dystrophy type 2I occurs with a frequency of approximately 1 in 3,500 live-born boys. The disease has an X-linked inheritance, which confirms its predominance among the male sex. Epidemiological studies show that this form of dystrophy is observed in different ethnic groups, but is most common among Caucasian men. In some cases, the incidence may vary depending on geographic location and access to medical care. All these data point to the importance of early diagnosis and referral to specialists to improve overall treatment outcomes.
Genetic predisposition to this disease
The main cause of limb-girdle muscular dystrophy type 2I is a mutation in the DMD gene, located on the short arm of chromosome 21. Mutations can be of different types: point, deletion or duplication, resulting in the absence or deficiency of dystrophin. The disease is inherited in an X-linked manner, meaning that boys who inherit the mutation from their mother will be susceptible to the disease, while girls are more often carriers but may experience milder forms. In recent years, other genes involved have been discovered, such as those responsible for the regulation of other proteins involved in muscle metabolism and structural integrity.
Risk factors for the development of this disease
The main risk factors that contribute to the development of limb-girdle muscular dystrophy include:
- A family history of muscular dystrophy, indicating a genetic predisposition.
- The age of the mother at pregnancy, since late pregnancy is associated with an increased risk of chromosomal abnormalities.
- Lifestyle and environmental factors, including exposure to chemicals or physical agents, although a clear link has not yet been established.
- Gender – this disease is expressed mainly in men.
- History of maternal illnesses associated with dystrophies or other hereditary diseases.
Diagnosis of this disease
Diagnosis of limb-girdle muscular dystrophy requires a comprehensive approach, including the following steps:
- Main symptoms: initial muscle weakness, especially in the hips and lower back, delay in reaching motor development milestones in children.
- Laboratory tests: blood test for creatine kinase (CK) levels, which are significantly elevated in dystrophy.
- Radiological examinations: MRI and ultrasound of muscles to assess the condition of muscle and connective tissue.
- Other diagnostic tests include genetic testing for mutations in the DMD gene and muscle biopsy.
- Differential diagnosis: exclusion of other types of muscular dystrophies and neurological diseases such as spinal muscular atrophy.
Treatment
Treatment of limb-girdle muscular dystrophy is aimed at slowing the progression of the disease and improving the quality of life of patients. The main approaches include:
- General treatment: Physical therapy and rehabilitation significantly increase the functional abilities of patients and improve their overall condition.
- Pharmacological treatment: use of corticosteroids to slow the decline in muscle strength.
- Surgical treatment: correction of scoliosis and improvement of limb position if necessary.
- Other types of treatment: use of special aids – walkers, wheelchairs and orthoses.
List of medications used to treat this disease
The following medications may be included in the treatment of limb-girdle muscular dystrophy:
- Prednisolone
- Deflazacort
- Ecosapentaenoic acid
- Medicines to support the cardiovascular system if needed (eg, ACE inhibitors)
- Muscle relaxants to reduce muscle tone.
Disease monitoring
Patient management includes regular check-ups and assessment of disease progression. Prognosis can vary widely, but most patients lose the ability to walk in their teens. The main complications to watch for are:
- Pulmonary complications associated with limited mobility.
- Cardiovascular disorders including cardiomyopathy.
- Limitation of shoulder girdle function and the possibility of surgical interventions.
Age-related features of the disease
The initial signs of limb-girdle muscular dystrophy usually appear between the ages of 2 and 6 years, with the disease progressing at different rates in different age groups. Children often have difficulty running, jumping, and climbing stairs. Adolescents have severe difficulties with mobility and personal care. Adult patients usually require constant care and support due to significant limitations in physical activity.
Questions and Answers
- What symptoms indicate the need to see a doctor? The main symptoms are muscle weakness, difficulty climbing stairs and frequent falls.
- Can this disease be prevented? Since the disease is genetic, it cannot be prevented, but early diagnosis can slow down its progression.
- What is the long-term prognosis for patients? The prognosis depends on the timeliness of diagnosis and initiation of treatment, but most patients lose the ability to walk in adolescence.
- Are there modern treatments that improve quality of life? Yes, modern rehabilitation methods and drug treatment significantly improve the quality of life and slow down the deterioration.
- What kind of care do patients with this disease need? The patient needs to be monitored regularly by a physician, receive physical therapy, and have access to mobility aids.
Advice from Dr. Oleg Korzhikov
"First of all, it is important to remember that every case is unique. I recommend that all parents whose children begin to show any signs of muscle weakness seek medical attention immediately. Regular physical activity and specially selected exercises will help slow the progression of the disease. Do not hesitate to ask questions of your doctors and seek the opinions of several specialists to ensure that your child is receiving the best care. In addition, it is important to support the patient's emotional state using psychotherapy and support groups for Families."
