What miopathy is?

Congenital myopathies are a group of rare genetic diseases in which the muscle fibers are damaged within their structure or display wrong metabolism. In addition to muscle hypoplasia, often leads to the defects in the bones and joints, which over time, leads to many difficulties in normal functioning of the patient.

There are many types of myopathies (i.e. central core myopathy, nemaline myopathy, myotubular myopathy, multiminicore disease). Each one may differ with the symptoms, the way of inheritance and prognosis. Some of them occur so rarely that are almost completely not examined nor named by today’s medicine.
Symptoms of congenital myopathies usually progress quite slowly - from the very beginning of the disease rather says same. 
In general, a child with myopathy is flabby  ("floppy infant syndrome"), less mobile, have poor reflexes, and the texture of the skeletal muscles within hand examination can be felt abnormal. Due to the significant weakening of the muscles all myopathies can be associated with a wide range of locomotors system diseases. 
The diagnosis
As mentioned, each of the myopathy is characterized by other symptoms and changes within the muscle. Hence crucial and valuable information muscle tests provides - such as biopsy and histochemical examination under the electron microscope, which shows the changes and damage of muscle structure and/or in the metabolism.
For diagnostic purposes electrophysiological studies are also very helpful, i.e. electromyography. However, the obtained result does not necessarily prove anything concrete - both mild deviations as well as norm can appear.
Laboratory tests of blood, targeted at the level of keratin kinase (CK), usually show normal values of this parameter, although it may also be slightly increased. Often genetic research is recommended, as well as the genetic counseling in specialized clinics.
How to cure?
Unfortunately congenital myopathies are incurable. An effective pharmacological treatment has not been developed yet for congenital myopathy. Any treatment aims to improve the daily life, and usually relies on an active rehabilitation, orthopedic interventions, surgical and implement simple changes in everyday life (including nutritional, caloric diet). It is helpful to get some professional help from occupational therapists, psychologists and speech therapists (especially in case seizure of muscle responsible for speech).
Besides, special attention should be drawn in case applying anesthesia as some of them may trigger symptoms of malignant hyperthermia.
In some cases it is necessary to assist breathing, and even the use of mechanical ventilation using a respirator.
In addition, the patient should be regularly monitored in terms of heart problems, because of a risk of cardiomyopathy.