An inherited myopathy caused by mutations in the ACTA1 gene, encoding actin, alpha skeletal muscle. The phenotype is highly variable, and as such attempts at classification by clinical features is not optimal. Generally, affected individuals have generalized muscle weakness, typically involving proximal muscles, the face, bulbar and respiratory muscles. The disease is MONDO_0008070 (congenital myopathy 2a, typical, autosomal dominant). Also known as: ACTA1 nemaline myopathy, CMYO2A, actin accumulation myopathy, actin accumulation myopathy (disorder), actin myopathy, congenital myopathy with excess of thin filaments, nemaline myopathy 3, autosomal dominant or recessive, nemaline myopathy caused by mutation in ACTA1.