The disruption to dopaminergic neurotransmission has been suggested to play a role in MD, with reduced DRD2 expression, higher levels of dopamine and its metabolites, increased release of dopamine in response to amphetamine in Sgce knock-out mice [69,70], and reduced DRD2 availability reported during brain imaging of patients diagnosed with MD [71]. The gene discussed is DRD2; the disease is Menkes disease.