SNCA and dementia: Although follow-up genetic studies have been inconsistent for some of them or conclusive data are still pending, there is evidence that five of those genes (a-synuclein, parkin, PTEN-induced putative kinase 1, DJ-1, and leucine-rich repeat kinase 2) cause typical PD [2], and mutations of ATP13A2 (PARK9) cause Kufor-Rakeb disease, an autosomal recessive parkinsonism with many other features, including pyramidal tract dysfunction, supranuclear gaze paresis, and dementia [3].