  A minimal lepton number violation (LNV) is proposed which could naturally
appear in SUSY theories, if Yukawa and LNV couplings had a common origin.
According to this idea properly implemented into MSSM with an additional
abelian flavor symmetry the prototype LNV appears due to a mixing of leptons
with superheavy Higgs doublet mediating Yukawa couplings. As a result, all
significant physical manifestations of LNV reduce to those of the effective
trilinear couplings $LL\bar{E}$ and $LQ\bar{D}$ aligned, by size and
orientation in a flavor space, with the down fermion (charged lepton and down
quark) effective Yukawa couplings, while the effective bilinear terms appear
generically suppressed relative to an ordinary $\mu $-term of MSSM. Detailed
phenomenology of the model related to the flavor-changing processes both in
quark and lepton sectors, radiatively induced neutrino masses and decays of the
LSP is presented. Remarkably, the model can straightforwardly be extended to a
Grand Unified framework and an explicit example with SU(7) GUT is thoroughly
discussed.
