  We explore low-scale leptogenesis in a class of supersymmetric SO(10) models
using extra singlet neutrinos and the Higgs representations {126}_H\oplus
{\ovl{126}}_H as well as {16}_H \oplus {\bar {16}}_H. A singlet neutrino, which
can be as light as 10^5-10^6 GeV, decays through its small mixings with
right-handed neutrinos creating a lepton asymmetry which is shown to be flavor
dependent. While the doublet vacuum expectation value in {\ovl{16}}_H triggers
the generation of desired mixings, it also induces a large RH triplet vev that
breaks the LR intermediate gauge symmetry and gives large RH neutrino masses.
Manifest unification of gauge couplings and generation of heavy RH neutrino
masses are achieved by renormalizable interactions. The canonical (Type-I)
see-saw contributions to the light neutrino mass matrix cancel out while the
Type-II see-saw contribution is negligible. Determining the parameters of the
dominant inverse see-saw formula using the underlying quark-lepton symmetry and
neutrino oscillation data, we show how leptogenesis under the gravitino
constraint is successfully implemented. New formulas for the decay rate and the
asymmetry parameter are derived leading to baryon asymmetry within the observed
range. The model is found to work for hierarchical as well as inverted
hierarchical light neutrino masses. Testable predictions of the model are RH
doubly charged Higgs bosons which may be leptophilic and accessible to the
Tevatron, LHC or a linear collider. In a model-independent manner, the
Drell-Yan pair production cross section is shown to be bounded between 59%-79%
of their left-handed counterparts with same mass. In contrast to single-step
breaking SUSY GUTs, which predict a long proton lifetime for p\to e^+\pi^0,
here this lifetime is substantially reduced, bringing it within one order of
the current experimental limit.
