TNNT2 and familial dilated cardiomyopathy: In addition to TTNtvs, our analyses identified rare protein-altering variants in 5 genes previously studied in patients with DCM.29 Mutations in BAG3, LMNA, MYH7, and TNNT2 are established autosomal dominant causes of DCM.14,35TCAP mutations are occasionally identified in patients with DCM,36 but more commonly cause a recessive form of limb-girdle muscular dystrophy.37 Despite the low prevalence of variants in these genes across all CCM cohorts (4.7%), their critical roles in myocyte biology imply that variants identified here may contribute to an individual’s risk for CCM.