Centronuclear Myopathy - Symptoms, Causes and Treatments

What is Centronuclear Myopathy?
Centronuclear myopathies is a group of congenital inherited disorder which causes generalized but severe hypotonia, muscle weakness (muscle tissues related problems) and abnormal location of cell nuclei in skeletal muscle cells (nuclei are located in the center of the cell as against near periphery). There are more than ten types of centronuclear myopathies, for example: myotubular myopathy (X-linked myopathy), autosomal myopathy (also known as autosomal recessive form), autosomal dominant dynamin 2-related form, autosomal dominant myogenic factor 6 related form etc. Some types of myopathies surface right from the birth (congenital) and some other show up later in life.

What are the symptoms of Centronuclear Myopathy?
Myopathy is basically a disease related to muscle tissues, and mild to severe hypotonia (muscle weakness, loss of muscle tone, problems with proximal muscles, skeletal muscles, weakness in facial muscles leading to various problems etc. and symptoms related to hypotonia) is the primary symptom of this disorder. They other symptoms of this disorder include breathing problems (hypoxia), scaphocephaly, drooping of eyelids and cramps in leg etc.

Causes of Centronuclear Myopathy:
All the types of myopathy disorders are inherited either from the mother or father, or both. The myotubularin form of this disease is X-linked recessive which mainly affects the male child and is inherited by a child through his mother.

As mentioned earlier, myopathies is a group of genetic disorders related to muscle tissues and is caused due to defect/mutation in the gene for myotubularin, myogenic factor 6 and dynamin 2 in the human chromosome. More than 75% cases that are diagnosed for myotubular myopathy are found to be carrying mutated MTM1 gene, autosomal recessive form related to mutation of BIN1 gene, and autosomal dominant form related to DNM2 gene (dynamin 2).

How is Centronuclear Myopathy diagnosed?
Muscle biopsy is used to determine if the nuclear is located in the center of the muscle cell or any other tissue related mutations, and confirm the type of myopathy disorder the patient is carrying. Almost all the appearances of muscle biopsy are similar in myotubular or centronuclear myopathy and the differences can only be revealed with the help of deep study. The other methods used to diagnose this disorder are: genetic testing to study mutation in genes, electrodiagnostic testing for nerve conduction studies and needle electromyography (in this method a thin needle like electrode is inserted into the muscle tissue in order to determine if there is any abnormal electric activity) etc.

Treatment
Unfortunately, there is no cure for centronuclear and myotubular myopathies. Symptomatic treatments are used in order to help patients suffering from myopathies. The symptomatic treatments used are: physical and occupational therapies (used to make muscles stronger and eliminate effects of hypotonia), therapies to improve functional ability of the patient, medication is also used to help cope with the internal problems (such as pulmonary complications, muscle weakening, eyelid drooping etc.) caused due to the disorder, use of supportive systems to help the patient perform essential tasks (such as respirator to help the patient breathe normally), treatment for scoliosis (either medication or surgery to remove scoliosis) etc.