Congenital Myopathies

Congenital myopathies are rare inherited disorders of muscles that affect your child from birth (congenital) or in infancy.

There are seven different types of congenital myopathies. All these types have some common features such as loss of muscle tone and weakness.

A child with congenital myopathies may also experience other symptoms like problems with

• feeding and breathing,
• skeletal abnormalities such as curvature of the spine (scoliosis),
• bone weakness (osteopenia)
• hip problems.

These signs and symptoms can manifest later in infancy or childhood. No cure has yet been discovered.

However, aggressive supportive treatments like physical, occupational and speech therapies, nutritional support, and assisted breathing can prolong life or increase level of activity.

You may consider genetic counseling to determine the risk of congenital myopathies in future pregnancies.

The signs and symptoms of congenital myopathies are similar to those produced by other conditions such as:

• congenital muscular dystrophies (CMD),
• congenital myasthenic syndromes (CMS)
• and others.

Some common signs and symptoms include:

• Muscle weakness
• Difficulty breathing or feeding
• Failure to grow
• Limited jaw opening
• Muscle contractures (deformity caused by shortening or hardening of muscles or tendons)
• Curvature of the spine (scoliosis)
• Foot drop (abnormal gait in which a child drags his/her foot)

Congenital myopathies are caused by genetic mutations affecting one or more genes. 

The signs and symptoms of congenital myopathies are not specific to the condition and it’s often difficult to make an exact diagnosis.

To make it worse, there are no diagnostic methods or criteria to pinpoint congenital myopathies. Your child’s doctor can refer your child to:

• Orthopedic surgeon
• Pulmonologist
• Cardiologist
• Gastroenterologist/dietician
• Geneticist/genetic counselor
• Physiatrist
• Physical/occupational therapist
• Orthotist

How to prepare yourself for the visit?

Getting prepared for the visit can optimize the therapy and help make the visit more fruitful. List out all the symptoms. 

Write down your child’s key medical information. Write down the names of all medications, vitamins or supplements.

Make a list of the questions to ask your child’s doctor

Some typical questions can be:

• What could be possible causes of the symptoms?
• What are the tests that my child needs?
• What are the treatment options?
• Can surgery provide relief?
• Do I have to make any changes in my child’s diet or activity?

What your doctor wants to know?

Prepare yourself to answer some essential questions from your child’s doctor.

S/he might ask you typical questions like:

• When did you start noticing the symptoms in your child?
• How severe are the symptoms?
• Do the symptoms occur continuously or occasionally?
• Does anything improve or worsen your symptoms?
• Do you have a family history of congenital myopathies or other similar conditions that affect muscles?

The diagnosis begins with a detailed physical exam helps to determine the cause of weakness.

If no other cause is detected, your child’s doctor can recommend following tests to eliminate other causes that may produce similar set of symptoms:

• Blood test to measure a muscle enzyme called creatine kinase, which is slightly increased in central core disease, a type of congenital myopathies
• Electromyogram (EMG) to assess the electrical activity of the muscle
• Nerve conduction study
• Muscle biopsy to eliminate other causes which present with similar signs and symptoms.
• Muscle ultrasound is also necessary in most cases
• Electrocardiogram (ECG) to determine the electrical activity in your child’s heart. Any abnormal ECG report indicates resultant heart problems

Congenital myopathies have no cure, however, a subtype called central core disease has an effective treatment.

Your child’s doctor can recommend supportive treatments such as orthopedic treatments, as well as physical, occupational or speech therapy help to lengthen life, preserve muscle activity and increase functional ability.

Treatment for congenital myopathies may include:

Medications

Airway widening drug salbutamol may help to reduce weakness in a subtype of congenital myopathies, central core disease. Other medications may be given to treat symptoms of some myopathies such as antibiotics can be administered early to treat respiratory infections, if any.

Nutritional and respiratory support

As the disease worsens with time, your child can be given nutritional or respiratory support (noninvasive ventilation).

Orthopedic treatments and surgery

Orthopedic support devices may help to correct or improve scoliosis, deformed foot. If they do not work, you may consider orthopedic surgery.

Physical, occupational or speech therapy

These therapies help to rehabilitate your child while reducing dependency as much as possible.

Follow-up care includes tests to measure muscle function, cardiopulmonary function.

Lifestyle modifications are necessary for your child in order to cope with congenital myopathies.

Having to see your child in such difficulty can be heartbreaking. Not much can be done to help your child but a positive turn of mind and stress management can help you better manage the situation.

Here are a few things that you can do to help your ailing child:

• Restrict your child’s calorie if s/he has severe mobility problems but DO NOT forget to provide essential nutrients.

• Take your child for some exercises. Regular exercise may help your child perform normal activities.

• Talk to a genetic counselor. Ask how this genetic defect can affect your future pregnancies or if there are any ways to prevent such condition in future.

There are several risks and complications associated with congenital myopathies.

Risks

• A family history

Complications

• Malignant hyperthermia (general anesthetic-induced rapid rise in body temperature and severe muscle contractions )
• Cardiac problems
• Respiratory failure