SV2A and Parkinson disease: The synaptic vesicle glycoprotein 2A (SV2A)is a presynaptic transmembraneprotein expressed in neurons across the brain and is critical forneural system functioning.1 It has beenused as a biomarker of synaptic density and is associated with a varietyof neurodegenerative and psychiatric disorders including Alzheimer’sdisease, Parkinson’s disease, and schizophrenia.