ACTA1related

ACTA1-related myopathies are a group of rare genetic muscle disorders caused by mutations in the *ACTA1* gene. This gene encodes the alpha-actinin-3 protein, which plays a critical role in muscle fiber structure and function, particularly in fast-twitch skeletal muscles. Mutations in *ACTA1* disrupt normal muscle development and maintenance, leading to progressive muscle weakness and other clinical manifestations.

The disorders associated with *ACTA1* mutations are collectively known as *ACTA1-related myopathies*, which include conditions such as nemaline myopathy, congenital myopathy, and distal myopathy. Symptoms vary depending on the specific mutation and age of onset, but common features include muscle weakness, hypotonia (low muscle tone), respiratory difficulties, and delayed motor milestones in childhood. Some individuals may also experience cardiac involvement, affecting heart function.

Diagnosis typically involves genetic testing to identify mutations in the *ACTA1* gene, alongside muscle biopsy and clinical evaluation. Treatment focuses on managing symptoms, as there is currently no cure for these conditions. Physical therapy, respiratory support, and assistive devices may improve quality of life. In severe cases, early intervention and multidisciplinary care are essential to address complications such as respiratory failure or cardiac dysfunction.

ACTA1-related myopathies are inherited in an autosomal dominant pattern, meaning an affected individual has a 50% chance of passing the mutation to each child. The condition is rare, with limited research available, which underscores the need for further study to improve understanding and treatment options. Genetic counseling is recommended for families affected by these disorders to assess risks and inform reproductive decisions.