  The existence of a light singlet fermion mixed with the electron neutrino is
hinted by the simultaneous explanation of various neutrino anomalies. We show
that supersymmetry can provide a natural framework for the existence and the
desired properties of such a fermion. Quasi Goldstone fermions (QGF) of
spontaneously broken global symmetries like the Peccei-Quinn symmetry or lepton
number can mix properly with the neutrinos provided the presence of the
R-parity breaking term $\e LH_2$. The lightness of QGF can be a consequence of
non-minimal K\"ahler potentials like that of no-scale supergravity. In order to
keep R-parity, such a sterile component has to be placed in a new singlet
superfield with no vacuum expectation value. In the context of the standard
seesaw mechanism the lightness of such a singlet can be understood by imposing
a $R$-symmetry.
