PSEN1 and dementia: Participants with dementia (n = 4), mild symptoms (n = 7), and asymptomatic (n = 28) from 13 families carrying variants in APP (n = 2) or PSEN1 (n = 11). Among families with a history of PSEN1 variants, one had L235V, one G206A, one S212Y, and eight had the A431E substitution. Number of carriers is not specified.