  There is a wide class of models which give a dynamical description of the
origin of flavour in terms of spontaneous symmetry breaking of an underlying
symmetry. Many of these models exhibit sum rules which relate on the one hand
mixing angles and the Dirac CP phase with each other and/or on the other hand
neutrino masses and Majorana phases with each other. We will briefly sketch how
this happens and discuss briefly the impact of renormalisation group
corrections to the mass sum rules.
