FBXO7 and Parkinson disease: The presynaptic nature of the parkinsonism in the families reported by Di Fonzo et al. is shown by the dramatic abnormality of DaTSCAN SPECT, the beneficial effect of levodopa, and the presence of levodopa-induced dyskinesias, suggesting that FBXO7 mutations may be the potential genetic causes of early-onset Parkinson's disease (EOPD) or familial PD [5].