Genetic Of Alzheimer’s Disease | Genetics Of Dementia | [Video]

There are two categories of genes that influence whether a person develops a AD:

(1) risk genes and (2) deterministic genes.

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1. Risk genes increase the likelihood of developing a disease but do not guarantee it will happen.

APOE-e4 is the first risk gene identified and remains the gene with strongest impact on risk.

APOE-e4 is one of three common forms of the APOE gene; ………
(the others are APOE-e2 and APOE-)

We all inherit a copy of some form of APOE from each parent.

Those who inherit one copy of APOE-e4 from their mother or father have an increased risk of developing Alzheimer’s.

Those who inherit two copies from their mother and father have an even higher risk, but not a certainty

2. Deterministic genes ….directly cause a disease, guaranteeing that anyone who inherits one will develop a disorder.

These genes, are estimated to account for 1% or less of Alzheimer’s cases,….. cause familial early-onset forms in which symptoms usually develop at early age

All of these genes affect processing or production of beta-amyloid, …..which is the protein fragment that is the main component of plaques.

Beta-amyloid is a prime suspect in decline and death of brain cells.