The gene encodes the D5 subtype of the Dopamine receptor. This subtype is a G-protein coupled receptor which stimulates adenylyl cyclase. Dopamine is one of the most important neurotransmitters and the expression of its receptors is well characterized in brain. Dopamine receptors are involved in many neurological processes so their abnormal signalling is implicated in several neuropsychiatric disorders. Defects in DRD5 are a cause of benign essential blepharospasm (BEB), a primary focal dystonia affecting the orbicularis oculi muscles.