The present results find auditory P300 trajectories associated with high familial risk for AD in males but not females in the 8–12 year old group. High-risk males in the 8–12 age range were 4.3 times more likely to be found in the low-level P300 group. The role of CHRM2 in the association between P300 developmental trajectories and familial risk was assessed. One SNP in this gene, rs1824024, was found to be associated with the trajectory characterized by lower P300 amplitude. Males were more likely to follow the low P300 trajectory, and if they were homozygous for the TT allele were much more likely to have a lower P300 trajectory during the 8–12 year old time period.
