MEIS1 and schizophrenia: DISC1 encodes a scaffold protein which is involved in brain development, and its mutations have been implicated in schizophrenia and other psychiatric disorders (Dahoun et al., 2017); MAOA encodes a mitochondrial oxidative deaminase targeting amines such as dopamine, norepinephrine, and serotonin, and mutations in the gene can result in Brunner syndrome, a psychiatric and sleep disorder (Brunner et al., 2007); MEIS1 is a HOX gene thought to have a pleiotropic effect on chronic insomnia disorder, and have possible association with restless leg syndrome (Sarayloo et al., 2019).