Figure 1.

The imprinted brain theory of autism and schizophrenia. This theory suggests that autism and schizophrenia are diametric opposites balanced by normal cognition (mentalism), in part caused by small-to-large genome-wide imbalances in imprinted genes or CNVs that have effects on neurodevelopment. Deviations can be either maternally or paternally biased (see Ubeda & Gardner [18,19] for further discussion of these effects), with smaller deviations influencing resource-demanding traits such as birth weight or suckling behaviour in offspring, whereas larger deviations lead to schizophrenia or autism, respectively (see [16,17]). Other causal factors (non-imprinted genes and environment) also contribute to the risk of these disorders.