Congenital Myopathy Knee Problems

Congenital myopathy refers to a group of muscle diseases with an underlying genetic defect that results in problems with muscles and muscle control. Generally, these myopathies show up in infants, who have insufficient muscle control or are unable to walk or develop normal ranges of motion. Although congenital myopathy affects movement, no specific knee problems are caused by congenital myopathies and congenital myopathy does not specifically target or affect the knees. However, a similar illness--congenital muscular dystrophy--does cause knee problems and has similiar syptoms in infants as congenital myopathy.

Congential Myopathy

• Congenital myopathy is a general medical term that refers to a group of muscle diseases that are inherited. The defect may be X-linked, autosomal (caused by neither the X nor Y chromosome) or autosomal dominant (in which only one parent must be a carrier for symptoms to be present). While most congenital myopathies have symptoms in infancy, and are present at birth, some do not cause symptoms for some time after birth. Congenital myopathies interfere with the communication between muscle cells and nerve cells, causing problems with skeletal muscles that make voluntary movement possible.

Congenital Myopathy & Knee Problems

• Congenital myopathies cause a number of problems with the muscular and skeletal system. Depending on the type of congenital myopathy, symptoms can include weakness, poor muscle tone, stiffness, enlarged muscles, skeletal deformities, scoliosis, difficulty walking or an inability to walk, and paralysis. None of these problems is specifically caused by or centered in the knee--they are more general symptoms throughout the body or in specific groups of muscles and joints.

Diagnosis

• If you are experiencing knee problems, coupled with overall muscle weakness and other symptoms, your doctor may recommend you be tested for congenital myopathies. (Congenital myopathy is diagnosed by blood tests, EMGs, ECGs, exercise tests, nerve condition studies, biopsies, thyroid tests, and/or genetic testing.) However, knee problems are not a specific symptom of congenital myopathy, especially if these knee problems come after infancy and are not accompanied by other symptoms.

Treatment

• There are no cures for congenital myopathy. Treatment generally is designed to minimize pain or symptoms and maximize quality of life. Treatment ranges from physical therapy and pain medication to lifetime hospitalization, depending on the severity and symptoms.

Congential Muscular Distrophy and Knee Problems

• A related but distinct illness, called congenital muscular dystrophy (CMD), can cause knee problems. Like congenital myopathies, CMDs are present at birth and are characterized by muscle weakness. Two specific types of congenital muscular dystrophies--Fukuyama CMD and Type IC--cause specific knee problems. CMDs can be misdiagnosed or confused with congenital myopathies; however, CMDs are distinct genetic problems. Those with congenital myopathies generally have developmental muscle abnormalities rather than the dystrophic muscle abnormalities present in those with CMD.