Does Alzheimer's run in families?

[Claire7880]

My grandmother has Alzheimer's and is now in a care home. It took the family a long time to get her diagnosed. It was a long and stressful situation all round. She was in her late 70's when she was diagnosed (a doctor gave us a leaflet on dementia and this was how we found out). I am concerned that my mother may also develop this awful illness. She is only in her 50's but complains about memory and the struggle to find the words she needs. She still works and is otherwise ok. I'm am unsure if I am just Paranoid that she will develop Alzheimer's as my grandmother has (and then obviously me in the future). So can it run in families?

[Dr Andrew McCaddon]

Hi Claire,

There are forms of Alzheimer's Disease that run in families, but they are quite different from the "late onset" type that your grandmother has developed, and they are much, much rarer. The affected family members tend to develop the disease at a much earlier age, often from mid-50s or even earlier. These types of dementia are due to genetic errors in relation to processing amyloid, the protein that is deposited in the brain in the disease. There are also some similar inherited forms in relation to the formation of "tangles" in brain cells. I am sure the Consultants here can provide additional details, but I would rest assured that it is extremely unlikely that these apply to your own circumstances.