We included a total of 4,343 clinically ascertained DCM cases from three datasets (Fig. 1 and Supplementary Tables 1 and 2), including two published DCM datasets8,10 (one reanalyzed; Supplementary Note) and a new clinical dataset from Amsterdam UMC (with one significant locus at BAG3; Supplementary Note, Supplementary Table 3 and Supplementary Figs. 1 and 2). This evidence concerns the gene BAG3 and familial dilated cardiomyopathy.