What age must a person be before which symptoms of early-onset Alzheimer's disease typically appear?

Early-onset Alzheimer's disease typically manifests in individuals before the age of 65. This form of Alzheimer's is rare and accounts for a small percentage of total Alzheimer's cases. The symptoms may begin to appear in individuals as young as their 30s and 40s, but the consensus in the medical community is that the onset generally occurs around the age of 60 or older, and primarily before 65. In contrast, the other ages mentioned in the options are not aligned with the generally accepted beginning range for early-onset Alzheimer's, which reinforces the validity of identifying 65 years as the cutoff age for typical symptoms to first appear.