  The simplest scenario for the three known light neutrinos that fits the solar
and atmospheric neutrino deficit and a mixed dark matter (MDM) picture of the
universe requires them to be highly degenerate with $m_{\nu} \sim$ 1 - 2 eV. We
propose an SO(10) grand unified model with an S$_{4}$-horizontal symmetry that
leads naturally to such a scenario.
  An explicit numerical analysis of the quark and lepton sector of the model
shows that it can lead to desired mass differences to fit all data only for the
small angle non-adiabatic MSW solution to the solar neutrino puzzle.
