NEUTRINO MASSES FROM GAUGE SYMMETRIES

A very simple extension of the Standard Model to include an Abelian fa mily symmetry is able to describe the hierarchy of quark and lepton ma sses and their mixing angles together with the unification of gauge co uplings. We consider the implications of this model for neutrino masse s and mixing angles and show that they are determined up to a discrete ambiguity corresponding to the representation content of the Higgs se ctor responsible for the Majorana mass matrix.