Adult Onset Nemaline Myopathy, also known as Adult Onset NM, is a rare hereditary neuromuscular disorder characterized by the presence of nemaline bodies in the muscle cells. Nemaline bodies are abnormal protein aggregates that disrupt muscle function and lead to weakness of the skeletal muscles.
This condition typically manifests in adulthood, usually after the age of 20, although it can occasionally appear in adolescence. The symptoms of Adult Onset NM include progressive muscle weakness and wasting, particularly affecting the limbs, resulting in difficulties with mobility, walking, and performing everyday tasks. Weakness in the facial muscles and throat may contribute to difficulties with swallowing, speaking, and facial expressions. Additionally, individuals with Adult Onset NM may experience respiratory problems, such as reduced lung capacity and shortness of breath.
The genetic cause of Adult Onset NM is usually inherited in an autosomal dominant manner, meaning that a mutation in a single copy of the responsible gene is sufficient to cause the condition. However, in some cases, a de novo mutation may occur, meaning that the mutation is not inherited from either parent but arises spontaneously during conception.
Although there is currently no cure for Adult Onset NM, treatment mainly focuses on managing the symptoms and optimizing quality of life. This may involve physical therapy to maintain muscle strength, assistive devices to aid mobility, respiratory support, and nutritional interventions. Genetic counseling may also be beneficial for affected individuals and their families to understand the inheritance pattern and potential risk of passing on the condition to future generations.
