Supplementary Data table 1

Variant noted to be present in 2 individuals

Variant: NM_000257.3(MYH7):c.1987C>T (p.Arg663Cys)

ClinVar: 42874, https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: n/a

Case14: Male, 59 years diagnosis, China, Asian

DiseaseAssertion: Hypertrophic Cardiomyopathy

FamilyInfo: One sibling had recurrent syncope and HCM with ICD implantation

CasePresentingHPOs: HP:0001639, HP:0001962, HP:0000822 (Hypertrophic cardiomyopathy, Palpitations, Hypertension)

HPOsFreeText: N/A

CaseNotHPOs: N/A

NotHPOsFreeText: N/A

CaseAddInfo: N/A

CasePreviousTesting: Probands were only genotyped for MYH7 and MYBPC3 in that order, stopping once a positive finding was detected.

CaseGenotypingMethod: Genomic DNA was extracted from peripheral blood. Each gene's coding exons and flanking introns were subject to PCR amplification and sequencing. From there, any variants found were filtered for pathogenicity and low frequencies.

Variant: NM_000257.3:c.1987C>T (p.Arg663Cys)

ClinVar: 42874 https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: Not in gnomAD

Case13: Male, 57 years diagnosis, China, Asian

DiseaseAssertion: Hypertrophic Cardiomyopathy

FamilyInfo: N/A

CasePresentingHPOs: HP:0001639, HP:0100749 (Hypertrophic cardiomyopathy, Chest pain)

HPOsFreeText: N/A

CaseNotHPOs: N/A

NotHPOsFreeText: N/A

CaseAddInfo: N/A

CasePreviousTesting: Probands were only genotyped for MYH7 and MYBPC3 in that order, stopping once a positive finding was detected.

CaseGenotypingMethod: Genomic DNA was extracted from peripheral blood. Each gene's coding exons and flanking introns were subject to PCR amplification and sequencing. From there, any variants found were filtered for pathogenicity and low frequencies.

Variant: NM_000257.3:c.1987C>T (p.Arg663Cys)

ClinVar: 42874 https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: Not in gnomAD

Supplementary Data Table S3

Case: 129

DiseaseEntity: HCM

HPOsFreeText: left ventricular hypertrophy (LVH) ≥15 mm

InheritancePattern: n/a

CasePreviousTesting: MYBPC3, TNNT2, TNNI3, MYL2, MYL3, TPM1, ACTC1 (59 genes total tested)

CaseGenotypingMethod: NGS of 59 genes (Supplemental Table S1), pathogenic and likely pathogenic variants confirmed via Sanger Sequencing

Variant: NM_000257.4(MYH7):c.1987C>T (p.Arg663Cys)

ClinVar: 42874 https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: Not in gnomAD

MultipleGeneVariants:

(1) LAMA4 Variant

Variant: NM_001105206.3(LAMA4):c.3239G>A (p.Arg1080Gln)

ClinVar: 44374 https://www.ncbi.nlm.nih.gov/clinvar/variation/44374/

gnomAD: 0.02400, https://gnomad.broadinstitute.org/variant/6-112460365-C-T

Table 1 and 4

Case 64: Male, 42yo

DiseaseAssertion: HCM

FamilyInfo: negative family history

CaseHPOFreeText: interventricular septum thickness = 18.1mm, left ventricular end diastolic diameter = 51.7mm, left ventricular end systolic diameter = 34.4mm, left ventricular posterior wall thickness = 9.8mm, left atrium = 44mm, left ventricular ejection fraction = 61%

CasePreviousTesting: 12-lead ECG, echocardiography, full testing (MYBPC3, TNNT2, TNNI3, MYL2, MYL3, TPM1, ACTC1), additional testing (LMNA, PRKAG2, SCN5A, MYH6)

CaseGenotypingMethod: genomic DNA collected from peripheral whole blood samples, PCR, high-throughput sequencing using PGM Sequencing 400 kit, variants verified via Sanger Sequencing

Variant: NM_000257.3(MYH7):c.1987C>T (p.Arg663Cys)

ClinVar: 42874, https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: n/a

Supplementary Material 4

Case M-10: 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: NM_000257.3(MYH7):c.1987C>T (p.Arg663Cys)

ClinVar: 42874, https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: n/a

Supplementary Material 4

Case M-9: 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: NM_000257.3(MYH7):c.1987C>T (p.Arg663Cys)

ClinVar: 42874, https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: n/a

CaseMYH7-1: N/A

DiseaseAssertion: Hypertrophic Cardiomyopathy

FamilyInfo: N/A

CasePresentingHPOs: HP:0001639 (Hypertrophic cardiomyopathy)

HPOsFreeText: N/A

CaseNotHPOs: N/A

NotHPOsFreeText: N/A

CaseAddInfo: N/A

CaseGenotypingMethod: Testing for all 8 sarcomeric genes, plus GLA, LAMP2, and PRKAG2 was initiated in all probands. After the direct sequencing, the variants were filtered for pathogenicity and classified.

Variant: NM_000257.3:c.1987C>T (p.Arg663Cys)

ClinVar: 42874 https://www.ncbi.nlm.nih.gov/clinvar/variation/42874/

gnomAD: Not in gnomAD