  A dynamical origin of the Yukawa couplings is a promising scenario to explain
the flavour puzzle. The focus of this letter is set on the role of the neutrino
Majorana character: when an $O(2)_{N_R}$ flavour symmetry acts on the
right-handed neutrino sector, the minimum of the scalar potential allows for
large mixing angles -in contrast to the simplest quark case- and predicts a
maximal Majorana phase. This leads to a strong correlation between neutrino
mass hierarchy and mixing pattern. Realistic solutions point to the existence
of three heavy right-handed neutrinos.
