PSEN2 and Alzheimer disease: PSEN2 mutations are reported to be associated with AD of both early onset and variable age onset as well as with other neurodegenerative disorders such as Lewy Body dementia, frontotemporal dementia, Parkinson dementia, and posterior cortical atrophy.2–4 In addition, PSEN2 has associations with breast cancer and dilated cardiomyopathy.3