Analogous to AD, Huntington disease and CJD [40], an accumulation of pathological aggregates through serine-protease-inhibitors – in addition to the role of alpha-synuclein in the pathogenesis of the disease [41], [42], [43] - can be assumed and PDD could therefore be a subgroup of neurodegenerative diseases with cerebral protein aggregation. The gene discussed is SNCA; the disease is neurodegenerative disease.