The 16y old with Ptau and Aβ1-42 in cortical and brainstem locations, α-synuclein in olfactory bulb, and TDP-43 in brainstem, exhibits an overlap of quadruple aberrant AD, PD, and TDP-43 and significant variations in the concentrations of ferrimagnetic material across his brain samples (Figure 7; Supplementary Table S2). Here, SNCA is linked to Parkinson disease.