  Quantum rings coupled to external nanowires offer a versatile platform for
the manipulation of the quantum mesoscopic transport. Here, we study such a
system, including periodically distributed pointlike impurities along the ring.
Based on an exact expression for the conductance found here, we demonstrate
that the bound states in the continuum (BICs) form from the ring states at the
high-symmetry momenta in the ring's Brillouin zone. Furthermore, the presence
of the inversion symmetry allows for a selective decoupling of resonant states,
favoring the BIC generation and, therefore, allowing extra tunability in the
quantum transport of the system. Finally, we suggest that the magnetic fluxes
and Rashba spin-orbit coupling offer other possible routes for the BIC
formation in laterally coupled quantum rings.
