Based on human epidemiological data and presence of chemicals in human samples (e.g., [4, 5]), chemicals that are linked to cognitive deficit in children, including learning and memory impairment (AO of the DNT AOPs) were identified and divided into two groups according to the KEs of the relevant AOPs: those were (1) impairment of BDNF synthesis and release associated with alterations of synaptogenesis (similar MoA), and (2) alteration of synaptogenesis through multiple mechanisms, not directly linked to changes of BDNF levels (dissimilar MoA). This evidence concerns the gene BDNF and Cognitive impairment.