Congenital myopathy — the congenital disease caused by genetically determined violations in a structure of muscular tissue. The congenital myopathy is shown by diffusion muscular weakness and decrease in a muscular tone which expressiveness considerably varies depending on a type of a myopathy. In hard cases the congenital myopathy can lead to death of the child from respiratory insufficiency. The congenital myopathy generally by results of a morphological research of the samples received at a biopsy of muscles is diagnosed; the electromyography, an ergometriya and a research of a muscular tone have only auxiliary value. The congenital myopathy can demand actions for fight against respiratory violations, providing probe food, correction of the available orthopedic deformations and so forth.
The term "congenital myopathy" is applied in neurology to the whole group enough rare hereditary diseases which have a similar clinical picture and are differentiated only on specific morphological changes in a structure of muscular tissue. Treat the most often met types of a congenital myopathy: a disease of the central core, not crimson myopathy, a miotubulyarny myopathy, a myopathy with multiple cores and congenital disproportionality of types of muscle fibers.
The congenital myopathy is genetically caused disease. Depending on a type of a myopathy anomaly can be localized in various loci of chromosomes and be descended is prepotent, retsessivno or is linked to the H-chromosome. Existence of an abnormal gene leads to violation of synthesis of this or that protein entering into structure of muscular tissue. As a result the structure of muscle fibers changes that negatively affects their sokratitelny ability and results in generalized muscular weakness. Usually congenital myopathy is shown at early children's age. Its symptoms remain during all life of the patient. In most cases the congenital myopathy is characterized by a good-quality current with weak progressing or at all without it.
Classification of a congenital myopathy
2 signs were the basis for classification of a congenital myopathy: existence of information on localization of gene anomaly and data on what protein of muscular tissue is defective. According to it the congenital myopathy with the known mutant gene and a certain defective protein (not crimson myopathy, a disease of the central core, a miotubulyarny myopathy), a congenital myopathy with uncertain defective protein, but the established mutant gene (the desmin-connected and aktinzavisimy myopathies) and a congenital myopathy for which both the gene, and defective protein remain unknown is allocated (a congenital disproportion of types of fibers, a tsentronuklearny myopathy, a myopathy with multiple cores).
Symptoms of a congenital myopathy
The congenital myopathy in the first months of life of the child is characterized by existence of a syndrome of "the sluggish child": diffusion decrease in a muscular tone, easy muscular weakness, bad development of muscles and the weakened sucking. In process of development of the child muscular weakness becomes more noticeable. It is shown by impossibility to rise from a floor, to climb on a chair, difficulties when walking and other operations which without problems are performed by other children of the same age. Muscular weakness at a congenital myopathy can be expressed in various degree. Usually its essential progressing is not observed. In hard cases the child cannot get on feet and is forced to move all life on a wheelchair. But those skills which were acquired by it are not lost any more.
The greatest danger of a congenital myopathy is connected with weakness of respiratory muscles. At moderate muscular weakness gradual development of respiratory insufficiency, frequent bronchopulmonary diseases is noted (bronchitis, focal pneumonia, stagnant pneumonia, etc.). The expressed weakness of respiratory muscles can lead to bystry development of respiratory insufficiency and death of the child at infantile age.
In certain cases the congenital myopathy is combined with dismorfichny lines (the high sky, the extended and narrow shape of a face) and skeletal anomalies (, scoliosis, a clubfoot, the shoemaker's breast, congenital dislocation of a hip).
Characteristic of separate types of a congenital myopathy
The disease of the central core is inherited autosomno-is prepotent, also separate sporadic cases are known. The congenital myopathy of this look is shown by a delay of motive development during the first year of life, it is found in adult patients less often, often is followed by weakness of mimic muscles. Small growth of patients and a fragile figure, existence of skeletal deformations is characteristic. At patients with this type of a congenital myopathy the increased risk of emergence of a malignant hyperthermia is noted. In a bioptata of muscular tissue reveal muscle fibers with single or multiple zones of an aseptic necrosis.
Not crimson congenital myopathy includes an aktinopatiya, a nebulinopatiya, a tropomiozinopatiya and a troponinopatiya. Its inheritance happens more often by the autosomno-prepotent principle, but also recessive inheritance and sporadic cases of incidence meets. The classical form of not crimson congenital myopathy is characterized by a syndrome of the sluggish child. The severe form is shown in the pre-natal period in the form of a fruit akineziya, and at the child's birth — heavy motive violations, weakness of face muscles and respiratory insufficiency. The easy form of this type of a congenital myopathy is diagnosed after the period of the early childhood, sometimes — at teenage age, and proceeds without weakness of facial muscles. There is also specific form of not crimson congenital myopathy at which development of an oftalmoplegiya, cardiomyopathy, syndrome of a rigidny backbone is possible. The morphological research finds existence in muscles characteristic palochko-or nitepodobny little bodies.
The Miotubulyarny congenital myopathy is more often inherited as autosomny at which muscular weakness is expressed in easy degree and can be observed both at girls, and at boys. The H-linked miotubulyarny congenital myopathy strikes only males and is characterized by heavier current with weakness of facial muscles, disorder of swallowing and respiratory function. In a bioptata of muscular tissue defeat of fibers I of type prevails. The central arrangement of kernels of miotsit is noted that corresponds to muscular tissue of an embryo for 8-10 weeks of pregnancy. Due to these most of researchers consider a miotubulyarny myopathy as result of an underdevelopment of muscular tissue.
The myopathy with multiple cores is more often observed as an autosomno-recessive disease though also the prepotent type of inheritance is possible. Muscular weakness in proximal departments which is observed at chest age is typical. Much less often the disease debuts at more advanced age. In such cases generalized muscular weakness is noted. In a muscular bioptat cages decide on lack of mitochondrions, destruction of sakromer and a hypotrophy of muscle fibers.
The congenital disproportion of types of muscle fibers is shown by generalized weakness of muscles including front, muscular hypotonia, anomalies of a skeleton. The type of inheritance of this congenital myopathy is not established yet. In a bioptata of muscles increase in quantity and the small size of fibers I of type against the background of a hypertrophy or the normal size of fibers II of type is observed.
Diagnostics of a congenital myopathy
Only aim survey with a research of muscular force and a tone allows the neurologist to suspect presence at the child of a congenital myopathy of mild cases. The careful research of muscles with conducting power testing (ergometriya), standard and stimulation electromyography, miotonometriya or elektrotonometriya allows to obtain the additional data testifying in favor of the diagnosis "a congenital myopathy". To exclude a generalized inflammatory myopathy (dermatomiozit, polimiozit) and diffusion miozit lack of a pain syndrome, consolidations and inflammatory puffiness of muscles allows.
Finally congenital myopathy can be diagnosed only after results of a morphological research of the muscular tissue received by a biopsy of muscles. Only this inspection allows to define myopathies of change, specific to each look, and to establish the exact diagnosis. However even the biopsy not always allows to verify type of a congenital myopathy authentically.
Treatment of a congenital myopathy
Unfortunately, today there are no enough effective ways of treatment and the congenital myopathy keeps the manifestations during all life of the patient. Possible methods of therapy are directed to maintenance of higher level of viability of the patient. If the congenital myopathy is followed by considerable decrease in muscular force, in the first months of life medical actions consist in fight against respiratory insufficiency, providing food via the gastric probe, knocking over of bronchopulmonary complications. The beneficial effect on a condition of patients at any age is exerted by massage, balneotherapy and physiotherapeutic procedures. At more advanced age orthopedic correction of the available violations and social adaptation of patients can be required.