QPRT and epilepsy: For example, MAPK3 is a synaptic signalling component which is reported to be necessary for several forms of learning (Mazzucchelli et al., 2002; Pucilowska et al., 2015) and quinolinate phosphoribosyltransferase encodes a key enzyme in catabolism of quinolinate, a potent endogenous exitotoxin to neurons, the elevation of which has been linked to the pathogenesis of epilepsy (Feldblum et al., 1988; Haslinger et al., 2018).