  We show that all mixing angles are determined, within experimental
uncertainty, by a product of SU(2) horizontal symmetries intimately linked to
the algebra of weak neutral currents. This concerns: on one hand, the three
quark mixing angles; on the other hand, a neutrino-like pattern in which
theta_{23} is maximal and tan (2 theta_{12}) = 2. The latter turns out to
exactly satisfy the ``quark-lepton complementarity condition'' theta_c +
theta_{12} = pi/4. Moreover, among all solutions, two values for the third
neutrino mixing angle arise, which satisfy the bound sin^2(theta_{13}) \leq
0.1: theta_{13} = +/- 5.7 10^{-3} and theta_{13} = +/- 0.2717.

High Energy Physics - Phenomenology