On 15 January 2019, the sponsor decided to stop the study prematurely due to lack of patient recruitment because of supply problems with 18 F-Florbetaben.

The main purpose of the study is to assess safety of a single dose of FBB followed by PET scan in individuals at risk of genetic Alzheimer's disease.

Inclusion Criteria:

• Adult children (> 18 yo) of genetic Alzheimer?s disease patients with a known mutation in PSEN1, APP o PSEN2 genes and who are either cognitively normal (CDR=0) or have mild symptoms of cognitive decline (CDR 0.5 or 1)
• According to the principal investigator, participants must be committed to participate and complete all study procedures.
• Has signed the Informed Consent Form voluntarily to participate in the study

Exclusion Criteria:

• Subjects that are not able to complete the study.
• Any major disease or history of a major disease, especially hepatobilliar disease (AST /ALT ? 5 x ULN) or advanced renal insufficiency (creatinine ? 2 x ULN)
• Current or previous history of alcohol abuse or epilepsy
• Allergic to Florbetaben or any of its constituents
• Multiple drug allergies and/or previous history of contrast allergy.
• Pregnancy or breast feeding or planned pregnancy during the study period
• Any disease or history of disease which, in the opinion of the investigator, can cause disturbance of brain function (e.g. vitamin B12 or folic acid deficiency, disturbed thyroid function)
• Evidence for any other neurological or psychiatric disease