TCF7L2 and type 2 diabetes mellitus: Pulizzi et al. demonstrated in the Helsinki Birth Cohort that fetal TCF7L2 genotype did not interact with birth weight to increase the risk of T2D in adulthood [15].TCF7L2 rs7903146 has been shown to have the strongest genetic effect on T2D and this result has been replicated in several studies [3-5].