A recent [18F]FP-CIT PET study has investigated differences in dopamine transporter (DAT) in three different phenotypes of MSA divided according to different patterns of glucose metabolism: MSA-Pm (only striatal hypometabolism), MSA-Cm (only cerebellar hypometabolism), and MSA-mixedm (both striatal and cerebellar hypometabolism) [83]. This evidence concerns the gene SLC6A3 and multiple system atrophy.