NNAT and obesity due to melanocortin 4 receptor deficiency: We undertook an analysis of the association between paternal overweight/obesity status and sperm methylation percentage at the regulatory regions of imprinted genes MEG3-IG, MEG3, PEG1/MEST, IGF2, H19,GRB10, NNAT,  NDN, SNRPN, SGCE/PEG10, PLAGL1, and PEG3. We found significant differences in DNA methylation patterns between overweight/obese men and men of normal BMI at multiple DMRs.