Dopamine transporter (DAT) imaging, such as positron emission tomography (PET) with [11C]2β-carbomethoxy-3β-(4-fluorophenyl) tropane ([11C]CFT) and single photon emission computed tomography (SPECT) with [123I]2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ([123I]FP-CIT; DaTscanTM, GE Healthcare), is a powerful tool in the differential diagnosis of idiopathic Parkinson’s disease (PD) from essential tremor or other secondary parkinsonism without nigrostriatal degeneration. This evidence concerns the gene SLC6A3 and Parkinson disease.