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 ��_{13} of a few percent are found.

3 pages, 1 figure, adapted from a talk given at "Now 2008", September 6-13 2008, Conca Specchiulla (Otranto, Italy)