Besides differential expression of neurodevelopmental genes, when analyzing the function of the other genes in the PsychGene NanoString profiles that showed significant expression differences, we noted, that, consistent with prior genetic studies implicating calcium channel genes55,56, five of the 34 (~15%) differentially expressed genes in the BD-patient neurons were calcium channel or other ion channel subunits (Fig. 5B): CACNA1E (calcium channel, voltage-dependent, R type, alpha 1E subunit; Cav2.3), CACNA1G (calcium channel, voltage-dependent, T type, alpha 1G subunit; Cav3.1), CACNB1 (calcium channel voltage-dependent beta 1 subunit), a regulator of alpha-1 subunit membrane targeting and voltage dependent activation and inactivation, CACNG8 (calcium channel, voltage-dependent, gamma subunit 8), a regulator of AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor localization, the sodium channel genes SCN2A (sodium channel, voltage -gated, type II, alpha subunit; Nav1.2) and SCN3A (sodium channel, voltage -gated, type III, alpha subunit; Nav1.3). However, due to the fact that our NanoString PsychGene probe set was purposely biased in its construction for coverage of genes relevant to neurodevelopment and neuropsychiatric disorder, it was not possible to calculate whether there was significant enrichment of any given functional category of genes amongst the set of differentially expressed genes.
