The Coleman–Oort conjecture for special subvarieties in the Torelli locus

Let $\mathcal{A}_g$ be the moduli space of principally polarized complex abelian varieties of dimension $g$, let $T_g$ be the Torelli locus, and let $T_g^o$ be its open Torelli locus. A subvariety $S\subset\mathcal{A}_g$ is special if it is an irreducible component of a Shimura variety. Coleman–Oort conjecture. For sufficiently large $g$, there are no positive-dimensional special subvarieties $S\subset\mathcal{A}_g$ contained in $T_g$ and meeting $T_g^o$. This follows formally from Coleman's conjecture together with the André–Oort conjecture, but the stated consequence is not resolved in the supplied text.