Additional Study Information: Funded by a multi-year research grant from the National Institute on Aging, the DIAN ObservationalStudy enrolls family members who have parents with a mutated gene known to cause dominantlyinherited Alzheimers (DIAD). Through the study, researchers follow individuals and family members tosee if insights gained could lead to better understanding of how the disease progresses in order toidentify solutions to prevent DIAD or minimize its impact.