These genetic variants are also individually and significantly associated, sometimes in opposite directions for both genders, with beta-amyloid levels (P < 0.001), senile plaque accumulation (P < 0.001) and choline acetyltransferase activity (P < 0.05) in, respectively, two of two, five of six, and three of six brain areas.
Gene dose was shown to have an effect on risk of developing AD, age of onset, accumulation of senile plaques in the brain, and reduction of choline acetyltransferase (ChAT) activity in the hippocampus of AD subjects.