  The approximated tri-bimaximal mixing observed in the neutrino oscillations
is a particular feature of a class of models characterized by the spontaneously
broken horizontal flavour symmetry A4. In this paper, it is presented an
analysis on the predictions of these models for relevant low-energy
observables. In an effective operator approach, these effects are dominated by
dim-6 operators, suppressed by the scale M of new physics. Indications for M
and an upper bound on \theta_{13} of a few percent are found.
