of C4A in association with schizophrenia risk variation was originally reported in the adult brain [48], where the authors provided data to support a role for this gene in synaptic pruning. Although this process is important for maturation of regions such as the frontal cortex in adolescence, it begins (and is for some brain regions pronounced) during the perinatal period [56]. Our findings thus suggest that as well as influencing synaptic pruning during adolescence, effects of C4 risk variation could initially impact neural connectivity at this early phase of synaptic refinement.
