IGF2 and obesity due to melanocortin 4 receptor deficiency: Imprinted gene regions tend to escape the usual widespread erasure of DNA methylation from the paternally derived genome in the preimplantation embryo soon after fertilisation.36 In support of paternal effects generally, there is a report of hypomethylation at the IGF2 DMR in umbilical cord blood being associated with paternal obesity suggesting a preconceptional impact of the obesity (and/or exposures related to it) on the reprogramming of imprint marks during spermatogenesis.37