Hyperthyroid myopathy occurs when the thyroid gland produces too much of the hormone thyroxine, leading to muscle weakness, some muscle wasting in hips and shoulders, and, sometimes, problems with eye muscles.
Centronuclear myopathy: weakness of voluntary muscles, including those on the face, arms, legs, and trunk; drooping upper eyelids; facial weakness; foot drop; affected muscles almost always lack reflexes.
When a child has primarily motor delays, conditions such as cerebral palsy, ataxia, spina bifida, spinal muscular atrophy (withering) and myopathy may be present.
However, for a child to have one type of myotonia congenita and some forms of nemaline myopathy, two defective genes must be inherited-one from each parents.
Diagnostic tests can help differentiate among the different types of myopathies, as well as between myopathy and other neuromuscular disorders.