SLC6A3 and Lewy body dementia: Although the diagnosis of probable DLB is supported by biomarkers of downstream neurodegeneration, such as dopamine transporter SPECT imaging, I-123 metaiodobenzylguanidine myocardial scintigraphy, and polysomnography, the diagnostic accuracy of these tests for DLB is still limited, at early stages of the disease.1–3