The congenital myopathies are a group of rare muscle disorders. They are not muscular dystrophies , although they are among the neuromuscular disorders covered by the Muscular Dystrophy Association. They are generally characterized by benign, non- or slowly progressive muscle weakness present at birth. The weakness is generally proximal , but may also be distal and affect the facial muscles.
Intelligence is almost always unaffected.
However, the myopathies vary greatly both in presentation and in severity. Not only do they vary between the types, there are variations within each type. The conditions are sometimes obvious at birth, but at other times not until early childhood or later. Some people with myopathies use wheelchairs, others walk with the assistance of braces or other aids, and some appear to have no difficulties with mobility. Yet all have the same problems with their muscles.