Which are the symptoms of Bethlem Myopathy?

Symptoms of Bethlem Myopathy

Bethlem Myopathy is a rare genetic disorder that primarily affects the muscles and connective tissues in the body. It is classified as a type of collagen VI-related myopathy, which means it is caused by mutations in the genes responsible for producing collagen VI, an essential protein for maintaining the integrity of muscles and connective tissues.

Muscle Weakness: One of the hallmark symptoms of Bethlem Myopathy is muscle weakness, which typically begins in childhood or early adulthood. The weakness is usually more pronounced in the muscles closest to the trunk, such as the hips, thighs, and shoulders. Individuals with Bethlem Myopathy may experience difficulty with activities that require muscle strength, such as climbing stairs, getting up from a seated position, or lifting objects.

Joint Contractures: Another common feature of Bethlem Myopathy is the development of joint contractures. Joint contractures occur when the muscles and tendons around a joint become tight and restrict the normal range of motion. This can lead to stiffness and limited mobility in the affected joints, such as the elbows, knees, and ankles.

Progressive Muscle Wasting: Over time, individuals with Bethlem Myopathy may experience progressive muscle wasting, where the muscles gradually decrease in size and lose their strength. This can result in a loss of muscle mass and a decrease in overall muscle function.

Delayed Motor Milestones: Children with Bethlem Myopathy may exhibit delayed motor milestones, such as delayed walking or difficulty with coordination and balance. These delays are often the first signs of the condition and may prompt further medical evaluation.

Skin Changes: Some individuals with Bethlem Myopathy may develop specific skin changes, including keloid scars and small bumps called subcutaneous nodules. Keloid scars are thick, raised scars that extend beyond the boundaries of the original injury, while subcutaneous nodules are firm, non-cancerous growths under the skin. These skin changes are not present in all individuals with Bethlem Myopathy but can provide additional clues for diagnosis.

Respiratory Complications: In severe cases of Bethlem Myopathy, respiratory complications may arise due to weakness in the muscles involved in breathing. This can lead to difficulties with breathing, especially during sleep, and may require respiratory support or intervention.

Other Possible Symptoms: While less common, some individuals with Bethlem Myopathy may experience additional symptoms, including muscle pain, fatigue, scoliosis (abnormal curvature of the spine), and hearing loss.

It is important to note that the severity and progression of symptoms can vary widely among individuals with Bethlem Myopathy. Some individuals may have mild symptoms and maintain a relatively normal quality of life, while others may experience more significant impairments that impact daily activities and mobility.