The gene may produce a protein that latches on to the toxic beta amyloid and makes it impossible for the body to dissolve. As a result, the beta amyloid accumulates as plaques in the brain. Molecules called free radicals may also play a role. Normally, free radicals play important roles in the body, such as helping the immune system fight off disease. However, too many free radicals can start to upset the delicate balance within a neuron.
Nerve cells producing beta amyloid seem also to produce more free radicals.
It may be the case that free radicals thus boost beta amyloid production.