Figure 2.

A schematic of sAPPα ‘s potential contribution to macrocephaly in ASD via the PI3K/Akt/mTOR/Rho GTPase translation pathway. Elevated sAPPα enhances PI3K/Akt/mTOR pathway activity, leading to activation of rho GTPase. The GTPase stimulates oligodendrocyte progenitors, which utilize NOTCH activity to mature into oligodendrocytes. Increased oligodendrocytes favor hypermyelination, which would lead to white matter brain overgrowth. The white matter overgrowth would contribute to ASD endophenotypes, i.e., macrocephaly, poor social functioning, or regression.