Specifically, in the congenital myopathies group, 6 patients (27.3%) harbored de novo variants in the following genes: ZSWIM6, OCRL, ATRX, SYNE1, NIPBL, and TUBB4A. In the muscular dystrophies group, 4 patients (19.0%) had de novo variants in the genes ARIDG, MCM3AP, STXBP1, and BPTF. Here, MCM3AP is linked to congenital myopathy with cores.