Type of disease: Rare conditions
Bethlem myopathy is a rare genetic disorder that is a type of congenital muscular dystrophy, or CMD. All CMDs involve muscle weakness and muscle decay, problems with the joints, shorter muscles, and shorter tendons. Tendons hold together muscles and bones. For individuals with Bethlem myopathy, symptoms include movement problems, skeletal problems, trouble breathing, and intellectual disability. Some individuals also have small bumps on the skin near elbows and knees and soft skin on the palms and the bottom of the feet.
The change that occurs in Bethlem myopathy happens in genes that make up collagen. Collagen helps support muscles. In individuals with this condition, muscle cells are not as supported since there is less collagen, and this leads to muscle weakness.
Bethlem myopathy can present anytime from before birth to adulthood. The condition usually gets worse over time, and 2/3 of individuals with the condition eventually need to use a walker or wheelchair. Diagnosis is made based on clinical symptoms. Treatment varies depending on each individual’s symptoms. Common treatments include physical therapy, stretching exercises, and splinting. Sometimes, surgery can be used to fix problems with the muscles or the tendons.
Bethlem myopathy can be inherited in either an autosomal dominant or in an autosomal recessive manner. We inherit our genes in pairs, typically one from each parent. Our genes are what control the growth, development, and function of our bodies. If a mistake or error occurs in a gene, it can cause problems. Autosomal dominant means an individual inherits only one copy of the changed gene, or mutation, that causes the condition. Autosomal recessive means an individual inherits two copies of the changed gene in order to develop the condition.
If you or a family member has been diagnosed with Bethlem myopathy, talk with your doctor about the most current treatment options.