DRD2 and psychiatric disorder: This gene set includes many genes encoding neurotransmitter receptors, such as DRD2 (OMIM 126450), DRD3 (OMIM 126451), GABBR1 (OMIM 603540), GRM2 (OMIM 604099), and HTR1A (OMIM 109760), which are strongly implicated in various psychiatric diseases, including ASD,20 and in neurodevelopment.21