Of the common PD and narcolepsy genes, several were directly associated with PD and narcolepsy behavioral phenotypes such as locomotion (DRD2, DRD3, DRD4, GDNF, SLC18A2), sleep (DRD2, DRD3, GRIN2A, HTR2A, NLGN1), circadian processes (CACNA1C, DRD2, DRD3, DRD4, GRIN2, MAPK1, NLGN1, PPARGC1A,), circadian entrainment (CACNA1C, GRIN2A, MAPK1), learning (COMT, DRD1, DRD2, DRD3 GRIN2A) and memory (COMT, DRD1, DRD2, DRD3, GRIN2A, HTR2A). The gene discussed is DRD3; the disease is narcolepsy.