SNCA and Cognitive impairment: Although clinical estimates are thought to under-estimate the prevalence of DLB, neuropathological studies typically estimate the prevalence of DLB to be approximately 15–20% of all dementia cases and recent data using synuclein amplification assays (SAA) have suggested that abnormal α-synuclein is present in up to 23% of memory clinic patients with cognitive impairment [3, 4].