Fig. 5

a Luciferase reporter assay showing the effect of regulatory variants on transcription. The cloned promoter variants of BRAF (chr7:140624223_G/A), DTNA (chr18:32072866_A/G), FKTN (chr9:108319991_A/C, chr9:108320330_G/A), and LARGE1 (chr22:34316416_C/T) reduced luciferase activity compared to reference sequences. The promoter variant of DSP (chr6:7541776_G/A), a second promoter variant of LARGE1 (chr22:34316687_G/A), and an enhancer variant of TGFB3 (chr14:76289218_A/G) significantly increased luciferase activity compared to reference sequences. *p < 0.05 versus reference sequence. All luciferase reporter assays were performed with three biological replicates, each with three technical replicates. b Volcano plot representing the effect of 46 regulatory variants on gene expression using MPRA. Twenty-five variants had significant differences in transcriptional activity between reference and alternative allele (FDR < 0.05, represented by the horizontal black line). Gray = CMP variant activity less than reference allele; black = CMP variant activity more than reference allele. c Totally, 67% of significant variants were associated with higher transcription activity of the reference allele. d Log2-fold transcriptional activity changes between alternative and reference allele sequences. e Representative graphs of MPRA counts of alternative allele (green) versus reference allele sequences (gray) of BRAF (chr7:140624223_G/A), DSP (chr6:7541468_T/C), and DTNA (chr18:32073296_C/G). All MPRA assays were performed in five independent biological replicates. MPRA massively parallel reporter assay, ref seq reference allele sequence, FDR false discovery rate, CMP cardiomyopathy.