  We introduce fully SGUTs, SUSY grand unified theories that, upon symmetry
breaking through the Higgs mechanism, decompose into a visible sector and an
extra sector where the dynamics of the extra sector gauge group is responsible
for SUSY breaking. Fully SGUTs thus have the important feature that all gauge
groups of the visible sector and the extra sector unify into a simple gauge
group at the SGUT scale, therefore generalizing the successful MSSM gauge
coupling unification to all the gauge couplings of the theory. By focusing on
the ISS SUSY-breaking mechanism in the extra sector, we show that it is
impossible to reproduce the MSSM matter content when there exists a metastable
ISS SUSY-breaking state.
