In this study, we screened for the amyloid beta precursor protein (APP) 665 (glutamic acid to aspartic acid), 670/671 (lysine to asparagine and methionine to leucine) and 717 (valine to isoleucine) mutations in 34 persons affected with familial Alzheimer's disease (AD) and 139 with sporadic AD, originating from eastern Finland, using polymerase chain reaction amplification and restriction enzyme digestion. We did not find any of these mutations in the APP gene in our study. We conclude that these mutations in the APP gene may be a very rare cause of AD in Eastern Finland and thus most Finnish familial AD will likely be due to other gene defects.