Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD) are age-related chronic neurodegenerative syndromes with the common features of cognitive decline, parkinsonian motor symptoms, and with an underlying pathology of alpha-synuclein aggregated in neuronal inclusions, so called Lewy bodies [1, 2]. The gene discussed is SNCA; the disease is dementia.