I just received word from my brother-in-law that my older sister was diagnosed with Alzheimer’s. She is only 66! I do not know much about the disease, but from what I have heard when it gets diagnosed late in life (such as 80+), it is not thought to be hereditary, but early onset Alzheimer’s is? Nobody else in our family has had it.
There is much information online, and the family will want to speak with the MD at some length and will want to research as much as they can.
Very sorry to hear of this diagnosis.
I wouldn't panic about the rest of the family, if you were going to. There are just too many uncertainties about types of dementia, causes of the types, genetic vulnerabilities, environmental exposures, lifestyle, you name it.
How is she?
According to Google searches "Younger onset dementia is used to describe any form of dementia that develops in people under the age of 65".
66, 65 - same to me.
Dementia dx under 60 has greater chance being linked to a family gene apparently (but siblings do not share all genes) & the chance is still low. Specifically with Alzheimer's Disease the rate is a whopping 99% not hereditary (per Dr Google).
Lifestyle & other health issues play a part apparently. Especially hx of strokes & other vascular diseases eg blocked arteries. Basically same as for risks for heart attack.
I've also heard lack of cutting social contact & hearing loss are both risk factors... Not sure if hearing loss causing less social life is why - so getting hearing aides & staying social may offset this.
Possibly poor sleep quality for many years also a risk.
So a healthy lifestyle seems to be the best prevention within our control.