Case2: 12-year-old boy (Patient 2) DiseaseAssertion: DCM FamilyInfo: Family history unremarkable. ParentalTesting: The MYBPC3 variant was inherited from his father. The father’s cardiac phenotype is not reported. CasePresentingHPOs: HP:0001644, HP:0003546 CaseHPOFreeText: Severely depressed biventricular function; heart transplantation for decompensated heart failure. CaseNotHPOs: CaseNotHPOFreeText: CasePreviousTesting: Previous WES was negative; the variant’s intronic region was not adequately covered. Genotyping Method: Whole-genome sequencing (WGS; Illumina NovaSeq 6000; aligned to hg19/GRCh37). FunctionalAnalysis: SpliceAI predicted a potential splicing effect; no functional assay in this patient is reported. Variant: NM_000256.3:c.1224-80G>A (heterozygous intronic variant) ClinVar: 693982 CAID: CA221697326 gnomAD: 0.0000637 AdditionalInfo: The authors classified the variant as a VUS in this DCM case because evidence for a MYBPC3–DCM relationship is limited. ClinVar currently reports a pathogenic/likely pathogenic aggregate classification, primarily in relation to HCM. Reanalysis found no second MYBPC3 variant.