RYR1 and nemaline myopathy: As examples, eight patients with core myopathy had pathogenic variants in RYR1, eight NM cases harbored the typical compound heterozygous combination of a nonsense or a frameshift variant with a splice site variant affecting an in-frame exon of NEB. We also detected heterozygous missense variants in the highly conserved ACTA1 gene in five patients with classical NM and nemaline rods on muscle sections.