Congenital myopathies (CM)

Symptoms

CM usually manifests at birth or shortly thereafter. Babies with CM tend to be floppy, have absent or reduced muscle reflexes, weak muscles and have delays in reaching their motor milestones such as rolling over, sitting up, and crawling. Babies may also appear to have long, expressionless faces due to weak facial muscles. 

Many subtypes of CM share some common symptoms although it is likely not all symptoms will be present. 

The course of a myopathy is usually non-progressive – that is, it usually does not worsen over a person’s lifetime. Some children with myopathies gain strength as they grow older.

Symptoms common in congenital myopathies:

• Delays and difficulty in achieving motor milestones 
• Respiratory (breathing) issues which can increase the risk of lung infections
• Nutrition problems which may include choking or coughing when eating or drinking, vomiting, reflux and constipation
• Growth patterns that do not align to standard growth charts
• The eyelids and eyes can be weak but most children are able to adapt sufficiently so as not to develop problems with vision. 
• Fatigue which could be attributed to muscles working differently. This can also result in higher calorie consumption.
• Orthopaedic issues including stiffness and shortening of the joints (contractures), curvature of the spine (scoliosis) and hip dislocation are prevalent as a result of weakness of supporting muscles in these areas.
• Deep tendon reflexes can be less responsive to stimuli (hyporeflexia) or don’t respond to stimuli at all (known as areflexia).
• Fluid in the ear canal can sometimes accumulate and cause discomfort, slight hearing loss, and ear infections.
• In rare cases lack of oxygenation due to breathing difficulties can cause indirect heart muscle damage.