As you know, there are many different chromosomal abnormalities that are laid back in the period of intrauterine development. The study of these pathologies involved in genetics. In recent years, this area of medicine is actively developing, therefore, in the near future, such diseases will be easier to diagnose and treat. Fortunately, these anomalies are very rare. This is due to improved fetal diagnosis. One of the pathologies associated with chromosomal abnormalities is Louis-Bar syndrome. In most cases, this disease is detected in the first year of an infant's life, but sometimes it makes itself felt only by 6-7 years.
Louis Bar syndrome - what is this pathology?
This pathology refers to congenital genetic defects. In most cases, it is inherited. Ataxia-telangiectasia (Louis-Bar syndrome) is extremely rare. This disease has specific manifestations that allow you to diagnose this pathology. To make an accurate diagnosis, you need a consultation of doctors who confirm or deny the presence of a terrible anomaly.
History and epidemiology of the disease
This syndrome is very rare. Its frequency is about 1 case per 40 thousand population. The disease was first discovered by the French woman scientist Louis Bar. Syndromes characteristic of this pathology, she combined into one nosology. This happened in 1941. After it was discovered several more cases of the disease around the world. Since this anomaly is extremely rare, it is impossible to say with certainty what the etiology of Louis-Bar syndrome is. It is believed that the onset of the disease does not depend on climatic conditions. Therefore, the syndrome can occur in any region. In addition, there is no data that would link the incidence with the patient's gender. That is, Louis-Bar syndrome with the same frequency is observed in both boys and girls.
Reasons for the development of pathology
This anomaly of development is laid in the first trimester of pregnancy. The disease is inherited only. The syndrome refers to autosomal recessive genetic pathologies. This means that the child will definitely inherit the disease if both parents have a chromosome disorder. If an anomaly is observed in one of them (regardless of gender), then the chance of developing Louis-Bar syndrome in a baby is 50%. The main reason for the mutation is a violation of the long arm of the 11th chromosome. The exact factors that lead to such genetic rearrangement are unknown. But there are a number of harmful effects that affect embryonic development. First of all, these are environmental factors (radiation, poisoning by toxic substances). Also in the first trimester of pregnancy, stress is very dangerous.
Louis Bar Syndrome: the pathogenesis of the disease
Like most congenital chromosomal pathologies, this syndrome covers several organs and systems at once. The main targets of this disease are the brain and human immunity. There is also a pronounced lesion of the skin. All clinical manifestations of this disease are associated with the mechanism of its development. First of all, degenerative processes in the central nervous system are observed. Namely, cerebellar ataxia. However, some of the elements do not develop (Purkinje fibers and granular cells). Other visible disorders are skin manifestations - telangiectasias. They are dilated vessels, which are especially pronounced on the face (injection of the sclera, auricles, nose). Cerebellar ataxia and telangiectasia are collectively called Louis-Bar syndrome. Children born with this disease can be distinguished in the first years of life, since the anomaly is manifested by severe physical disorders (developmental delay, unstable body position, muscle weakness).
In addition , the pathogenesis of the disease includes a deficiency of the immune system (T-lymphocytes). In children suffering from this pathology, hypo- or complete aplasia of the thymus is observed. As a result of this, cellular immunity is very poorly developed and is not capable of protecting the body from infectious processes.
Symptoms of ataxia-telangiectasia
The severity of the clinical picture depends on the degree of damage to the cerebellum and hypoplasia of the thymus gland. This determines how Louis-Bar syndrome will manifest itself. Symptoms of the disease:
- Cerebellar ataxia. This syndrome manifests itself earlier than others, usually in the first year of life. It becomes pronounced at the time the independent walk begins. Children with cerebellar ataxia often cannot stand and move normally. In more favorable cases, there is an unsteady gait and tremor of the extremities. In addition, neurological symptoms are expressed in muscle weakness, dysarthria of varying degrees (slurred speech) and strabismus.
- Teleangiectasia. Skin manifestations of Louis-Bar syndrome are less dangerous. Usually they make themselves felt at the age of 3 to 6 years. Teleangiectasias are dilated capillaries called vascular asterisks. Most of all they are visible in open areas of the body, in particular on the face. Dilated vessels are often found in the eyes, on the nose and ears, as well as the flexion surfaces of the arms and legs.
- Tendency to infections. Due to severe immunodeficiency, the body does not cope with harmful agents on its own. As a result, a child often develops various infections. Often these are chronic diseases of the respiratory tract - pharyngitis, laryngitis, tonsillitis, pneumonia.
- Tumor processes. Due to thymic hypoplasia, in addition to infectious processes, the body becomes susceptible to cancer. Most often these are tumors of the blood-forming and lymphoid tissue. If Louis-Bar syndrome in a child is a reliable diagnosis, then it is strictly forbidden to treat cancer with ionizing radiation.
Diagnosis of ataxia-telangiectasia
Diagnosing Louis-Bar syndrome usually does not present much complexity, since its symptoms are quite specific. This disease can be suspected from the first years of life according to the clinical picture. Neurological symptoms (cerebellar ataxia, muscle weakness, tremors and strabismus) in combination with telangiectasias are an indication for the diagnosis of this pathology.
If you suspect Louis-Bar syndrome, you need to consult several specialists at once. Among them: a neurologist, dermatologist, oncologist, infectious disease specialist, endocrinologist and geneticist. In addition to clinical examination, laboratory and instrumental diagnostics are performed. Immunological analyzes are carried out, in which there is a decrease or complete absence of elements of cellular immunity (decrease in T-lymphocytes, immunoglobulins A, G). In the KLA, leukocytosis and acceleration of ESR are observed, which indicates an inflammatory process in the body. Instrumental diagnostics is also important. A chest x-ray (reduction of the size of the thymus), MRI of the brain (degenerative processes) is performed. Currently, in addition to standard studies, a genetic test is being carried out (a violation of the 11th chromosome is being investigated), based on which an accurate diagnosis is made.
Louis Bar Syndrome Treatment
Unfortunately, the etiological treatment of chromosomal abnormalities has not yet been developed. Therefore, with this pathology, only symptomatic therapy and constant monitoring of the patient are carried out. First of all, treatment is aimed at improving the functioning of the immune system. This is necessary to avoid infections and tumor processes. For this purpose, use gamma globulin and the drug "T-activin". With the development of inflammatory diseases, antibacterial and antiviral agents are used. Unfortunately, cerebellar ataxia syndrome cannot be completely treated. To stop the degenerative processes, nootropic drugs are used. With cancer, they resort to chemotherapy and surgical treatment.
The prognosis for life with Louis-Bar syndrome
Despite the severity of the disease, with timely diagnosis and treatment, it is possible to extend and facilitate the life of the child. To this end, palliative therapy has been developed for such patients. Unfortunately, the Louis Bar anomaly can progress quickly. In this case, the life expectancy is 2-3 years. Sometimes the disease does not develop for several years. Moreover, life expectancy is significantly increased. The maximum age of patients is considered to be 20-30 years. In most cases, the causes of death are infectious and tumor processes, sometimes neurological disorders.
Louis Bar Syndrome Prevention
To avoid the development of this pathology, it is necessary to conduct a genetic examination of the fetus in the early stages of pregnancy. It is also important to know the history not only of the parents of the unborn child, but also of other family members. During pregnancy, the harmful effects of the environment and psychoemotional stresses must be avoided.
If a baby with such an anomaly has already been born, it is important to carry out all the doctor's prescriptions and protect the child from infectious agents. With weak immunity and impaired physical development, it is necessary to timely diagnose Louis-Bar syndrome. Photos of children with this disease can be seen in the special medical literature.