On her Genetics & Health Blog, Hsien Hsien Lei, PhD talks about some of the latest genetic research as it regards Alzheimer’s and mutations in the presenilins genes 1 and 2.  Check this out at: http://www.geneticsandhealth.com/2006/09/21/presenilins-genes-and-alzheimers-disease   
You’ll discover additional information about the possibility of Alzheimer’s symptoms arising from mutant genes at: www.forbes.com/forbeslife/health/feeds/hscout/2006/09/19/hscout534916.html
Don’t be discouraged if you don’t understand articles and research that gets fairly detailed or scientific.  I’m trying to find information for readers with a variety of knowledge and interests and caregiving levels.  I’m pleased we’re beginning to find so much research going on with this disease.