We found variants in TPM1 and VCL to occur significantly more often than expected in pediatric DCM (TPM1: 10 of 12 carriers for whom age of onset was known were <18 years of age, FDR-adjusted exact binomial test P=2.7×10−2, VCL: 5 of 5 <18 years, P=4.3×10−2; details in Notes in the online-only Data Supplement). This evidence concerns the gene TPM1 and familial dilated cardiomyopathy.