How is myofibrillar myopathy diagnosed?

A diagnosis of myofibrillar myopathy is made based on clinical evaluation of the patient’s symptoms as well as tests such as electromyography (EMG), nerve conduction studies (NCV) and muscle biopsy.

How does myofibrillar myopathy affect the body?

Myofibrillar myopathy is part of a group of disorders called muscular dystrophies that affect muscle function and cause weakness. Myofibrillar myopathy primarily affects skeletal muscles, which are muscles that the body uses for movement. In some cases, the heart (cardiac) muscle is also affected.

What is desmin myopathy?

Desmin myopathy is a recently identified disease associated with mutations in desmin or alphaB-crystallin. Typically, the illness presents with lower limb muscle weakness slowly spreading to involve truncal, neck-flexor, facial, bulbar and respiratory muscles.

What are symptoms of myopathy?

The myopathies are neuromuscular disorders in which the primary symptom is muscle weakness due to dysfunction of muscle fiber. Other symptoms of myopathy can include include muscle cramps, stiffness, and spasm. Myopathies can be inherited (such as the muscular dystrophies) or acquired (such as common muscle cramps).

What happens to a child with BAG3 related myopathy?

Children with desminopthies may present with cardiomyopathy. Children with BAG3-related myofibrillar myopathies may present in the first or second decade with proximal weakness, respiratory failure and restrictive cardiomyopathy and are frequently rapidly progressive and fatal.

How is a diagnosis of myofibrillar myopathies made?

A diagnosis of myofibrillar myopathies is made based on clinical findings, electromyography, nerve conduction studies and muscle biopsy. Molecular genetic testing for the DES, CRYAB, MYOT, LDB3 and ZASP genes is available to confirm the diagnosis. Molecular genetic testing for the BAG3 gene is available on a research basis only.

What kind of disease is caused by BAG3 mutations?

That BAG3 mutations are responsible for familial dilated cardiomyopathy is confirmed by another study describing 6 new molecular variants (2 missense and 4 premature Stops ). Moreover, the same publication reported that BAG3 polymorphisms are also associated with sporadic forms of the disease together with HSPB7 locus.

How to tell if you have cardiomyopathy or myopathy?

Some also have muscle stiffness, aching, cramps or decreased muscle mass (atrophy). Pain, loss of sensation and inability to control muscles may also occur in one form (Filamin C protein mutations). Cardiomyopathy is sometimes the presenting symptom and may manifest as arrhythmia, conduction defects or congestive heart failure.