Pleiotropic genes were involved in gene regulation, synaptic function, and neuronal and dendritic development (Fig. 5b). They showed a distinct peak at mid-gestation, consistent with the overall developmental expression patterns of psychiatric disorder-associated genes (Fig. 5c). Finally, pleiotropic genes showed strong excitatory neuronal enrichment for cortical projection neurons in cortical layers 2/3 (excitatory neuronal subtypes 1) and corticothalamic projection neurons in cortical layers 5/6 (excitatory neuronal subtype 7) (Fig. 5d).
