PSEN1 and Alzheimer disease: We measured RyR-evoked calcium release in PS1 mutant HiNs, and found that the AD PS1 HiNs have exaggerated RyR calcium responses compared to cognitively normal controls (Data representative of all HiNs sampled (Non-AD n=125 ([Clone 17:n = 17] [Clone 37:n = 13] [Clone 38:n = 49] [Clone 46:n = 20] [ Clone 67:n = 25]) AD=189([ Clone 11:n = 28][ Clone 25:n = 74][ Clone 26:n = 24][ Clone 49:n = 16][ Clone 60:n = 47]).