  In this proceeding we present predictions of the effective Majorana mass
$|m_{\beta\beta}|$ in neutrinoless double-$\beta$ decay for the standard $3\nu$
mixing case and for the 3+1 neutrino mixing case indicated by the
short-baseline anomalies. We have taken into account the uncertainties of the
neutrino mixing parameters determined by oscillation experiments. We obtained
that the predictions for $|m_{\beta\beta}|$ in the cases of $3\nu$ and 3+1
mixing are quite different, in agreement with previous discussions in the
literature, and that future measurements of neutrinoless double-$\beta$ decay
and the total mass of the three lightest neutrinos in cosmological experiments
may distinguish the $3\nu$ and 3+1 cases if the mass ordering is determined by
oscillation experiments.
