The following information may help to address your question:
What is Bethlem myopathy?
is a rare disease affecting the skeletal muscles and connective tissue
. The disease is characterized by slowly progressive muscle weakness and joint stiffness (contractures
). It most often affects the fingers, wrists, elbows, and ankles.
Signs and symptoms may begin before birth (with decreased fetal movements), shortly after birth (with low muscle tone or torticollis), in early childhood (with delayed motor skills, muscle weakness, and contractures), or in adulthood (with weakness, Achilles tendon, or finger contractures). Due to the disease's progression, most people with Bethlem myopathy over age 50 require mobility aids (such as a cane, crutches, or wheelchair) for outdoor mobility. Rarely, severe muscle weakness may lead to respiratory difficulties in later life.
Bethlem myopathy is caused by mutations
(changes) in the COL6A1, COL6A2,
or COL6A3 genes
. Most cases are inherited
in an autosomal dominant
manner, but in rare cases the disease is autosomal recessive
The diagnosis is based on clinical examination and laboratory tests, but genetic testing
may confirm the diagnosis.
Treatment depends on individual symptoms but routinely involves physical therapy
. Surgery to correct joint contractures may be needed.
Last updated: 5/29/2018
What are the symptoms of Bethlem myopathy?
Bethlem myopathy mainly affects skeletal muscles, which are the muscles used for movement. People with this disease experience progressive muscle weakness and joint stiffness (contractures)
in their fingers, wrists, elbows, and ankles. The features of Bethlem myopathy can appear at any age. In some cases, the symptoms start before birth with decreased fetal movements. In others, low muscle tone (hypotonia
) and a stiff neck (torticollis
) develop during infancy. During childhood, developmental delay
may be noted. For example a baby with Bethlem myopahy may learn to sit by themselves or walk later than usual. In some, symptoms don’t occur until adulthood, when a person may notice muscle weakness. By the age of 50-years-old, approximately two-thirds (66%) of people with Bethlem myopathy will need to use a walker, cane, or wheelchair.
In addition to the muscle problems, some people with Bethlem myopathy have skin abnormalities. These abnormalities may include small bumps called follicular hyperkeratosis
that develop around the elbows and knees or soft, velvety skin on the palms and soles. Some people may also have wounds that split open with little bleeding and widen over time to create shallow scars.
Rarely, individuals with Bethlem myopathy may develop breathing problems as the disease progresses.
Last updated: 9/8/2017
How might Bethlem myopathy be treated?
Treatment for Bethlem myopathy is symptomatic and supportive. This means that treatment aims to relieve symptoms and improve quality of life. There is currently no cure for the disease, and there are no specific medications for Bethlem myopathy. In many cases, physical therapy
, stretching exercises, braces, splints, and mobility aids such as a walker or wheelchair are helpful. In rare cases, surgery may be needed to help with joint contractures
Last updated: 9/8/2017
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