Fig. 1.

a ADAOO distribution in 78 patients with Alzheimer’s disease carrying the PSEN1 E280A mutation. Notice the presence of two hidden groups with an average ADAOO of ~ 46 and ~ 51 years old, respectively. To identify these groups, a mixture of two Gaussian distributions was fitted as implemented in the mixtools [33] package for R [34]; the number of hidden groups was determined based on the log-likelihood criterion (the lowest the better). The blue vertical line is at ~ 48 years, which corresponds to the average ADAOO in our sample. Box and violin plots for the ADAOO by b gender, c early onset, and d education group. Only differences in the average ADAOO were found by AD status. e ADAOO as a function of the years of education. AD Alzheimer’s disease, ADAOO Alzheimer’s disease age of onset