Neuropathological examination of her paternal cousin (family member IV25), who died with Parkinson’s disease with dementia, disclosed advanced diffuse Lewy body disease.5,43,81 In line with the clinical presentation at advanced disease of dementia with gaze palsy, frontal release signs, retrocollis and speech apraxia indicating a concomitant tau pathology, we also found middle-stage Alzheimer pathology,45–48,80,81 advanced argyrophilic grain disease,49 as well as cerebral and leptomeningeal microangiopathic changes in family member IV25. Here, MAPT is linked to Lewy body dementia.