PSEN2 and Alzheimer disease: Brain tissue from carriers of PSEN1 (n = 9) including: A79V (n = 1), A260V (n = 1), F105L (n = 1), Y115C (n = 1), A431E (n = 1), V261F (n = 1), V261I (n = 1), M146L (n = 1), P264L (n = 1); N141I of PSEN2 (n = 1) carrier; subjects with sporadic AD (n = 4), and healthy controls (n = 2).