Two genes harbored variants with established cardiac pathogenicity (Supplementary Table S3): (1) variants in TTN were associated with multiple cardiac phenotypes including dilated cardiomyopathy (OMIM: 604145), hypertrophic cardiomyopathy (OMIM: 613765), limb-girdle muscular dystrophy with cardiac involvement (OMIM: 608807), and myopathy with early-onset fatal cardiomyopathy (OMIM: 611705); and (2) variants in MST1 were associated with immunodeficiency syndromes (OMIM: 614868) that can present with cardiac manifestations. Here, TTN is linked to myopathy.