The c.1074G>T (p.Trp358Cys) variant in ACTA1 is a missense variant predicted to cause substitution of tryptophan by cysteine at amino acid 358. This variant is absent from gnomAD v4.1.0 (PM2_Supporting). The computational predictor REVEL gives a score of 0.957, which is above the threshold of 0.7, evidence that correlates with impact to ACTA1 function (PP3). ACTA1, in which the variant was identified, is defined by the ClinGen Congenital Myopathies VCEP as a gene that has a low rate of benign missense variation and where pathogenic missense variants are a common mechanism of disease (PP2). This variant has been reported in 2 probands, one with nemaline rods in muscle biopsy (as well as dilated cardiomyopathy) and the other an infant with hypotonia (PS4_Supporting, PP4_Moderate; PMID: 23650303, Invitae SCV001393788.5). In summary, this variant meets the criteria to be classified as likely pathogenic for autosomal dominant alpha-actinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen Congenital Myopathies VCEP: PP4_Moderate, PS4_Supporting, PM2_Supporting, PP2, PP3. (Congenital Myopathies VCEP specifications version 2; 08/27/2024)