  In this paper we present the main results of our investigation of the $cq
\bar{q} \bar{q}$ single-charm scalar tetraquarks and their SU(3)$_\mathrm{F}$
representations: $\bar{15}_S$, $\bar{3}_S$, $6_A$ and $\bar{3}_A$. We use the
Fermi-Breit interaction Hamiltonian with SU(3) flavor symmetry breaking to
determine the masses of the single-charm tetraquarks. We also discuss mass
spectra obtained from meson and baryon mass fits. The mass spectra are very
similar to those obtained with Glozman-Riska hyperfine interaction, and they
indicate that some of the experimentally detected states may have tetraquark
nature.
