Similar findings were reported in a DAT-SPECT study, see [57], which reported evidence of striatal dopaminergic neuronal terminal loss in presymptomatic (G2019S) LRRK2-NMCs compared to NMNCs, indicating that this group might reflect an endophenotype where several of these NMCs would convert to definite PD [56,57]. The gene discussed is SLC6A3; the disease is Parkinson disease.