Supplementary Material 4

Case M-1: Japanese

DiseaseAssertion: idiopathic cardiomyopathy (HCM and DCM)

CasePreviousTesting: Clinical evaluation, chest radiography, electrocardiography, echocardiography, cardiac catheterization, full testing (MYBPC3, TNNT2, TNNI3, MYL2, MYL3, TPM1, ACTC1)

CaseGenotypingMethod: 8 sarcomeric genes amplified from genomic DNA via PCR then screened using bidirectional direct sequencing

Variant 1: NM_000257.3:c.175G>A

CAID: CA029319, http://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_caid?caid=CA029319

gnomAD: 0.000007955, https://gnomad.broadinstitute.org/variant/14-23902767-C-T

Variant 2: NM_000257.3(MYH7):c.1357C>T (p.Arg453Cys)

ClinVar: 14089, https://www.ncbi.nlm.nih.gov/clinvar/variation/14089/

gnomAD: n/a