A study using (99m)Tc-[2[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[1–3]-oct-2-yl]-methyl](2-mercaptoethyl)amino]ethyl]amino]ethane-thiolato(3-)N2,N2’, S2,S2]oxo-[1R-exo-exo)]) ([99mTc]TRODAT-1) and [123I]Iodobenzamide ([123I]IBZM) SPECT in three siblings with genetically confirmed HD revealed reduced [99mTc]TRODAT-1 and [123I]IBZM uptake compared to healthy controls indicating reduced striatal DAT and D2 receptor binding potentials respectively in HD patients, and reduction in D2 receptor binding potentials showed a correlation with functional status [50]. Here, SLC6A3 is linked to Huntington disease.