In ASD and VSD patients, 9 genes showed methylation changes, as compared with control group, whereby 2 imprinted genes (the GRB10 and MEST) were hypermethylated (Fig. 2a, b; Additional file 9: Figure S9a) and 7 (PEG10, NAP1L5, INPP5F, PLAGL1, NESP, MEG3 and H19) hypomethylation (Fig. 2c–i; Additional file 9: Figure S9a). This evidence concerns the gene NAP1L5 and ventricular septal defect.