Autism, psychosis, and genomic imprinting: recent discoveries and conundrums

Genomic imprinting generates a category of genes that is unique because: (1) they are subject to intragenomic conflicts, within individuals, and thus (2) their phenotypic effects on offspring-to-mother interactions are predictable from evolutionary theory. I describe recent advances in our understanding of how imprinted genes may exert conflicting effects, and how the sequelae of such conflicts may impact upon aspects of human behavior and risks for specific psychiatric conditions. The main conclusion is that imprinted genes mediate expression of many penetrant human social-brain disorders including autism and psychosis. However, discerning the targets, mechanisms, and large-scale significance of their effects requires more studies of small, SNP-based and methylation-based imprinted gene effects on phenotypes relevant to offspring-mother social interactions in typical populations.