Moreover, mutations in LRRK2 known to cause parkinsonism are associated not only with dopaminergic neuronal degeneration, but also with the accumulation of synuclein, tau, neither, or both proteins.
Post-mortem studies have demonstrated synuclein-positive Lewy body formation in the brains of individuals with parkinsonism who were also in the family described here and who also carry this triplication.
PET of the nigrostriatal system in parkinsonism associated with a mutation in the ac-synuclein gene indicates that it results in a pattern of dopamine deficiency, with preserved D2 binding, indistinguishable from IP.
A pathogenic point mutation within the a-synuclein gene has recently been identified in one Italian-American kindred and three families of Greek origin with parkinsonism.