  n this article we study the Friedel phase of the electron transport in two
different systems of quantum dots which exhibit bound states in the continuum
(BIC). The Friedel phase jumps abruptly in the energies of the BICs, which is
associated to the vanishing width of these states, as shown by Friedrich and
Wintgen in Phys. Rev. A \textbf{31}, 3964 (1985). This odd behavior of the
Friedel phase has consequences in the charge through the Friedel sum rule.
Namely, if the energy of the BIC drops under the Fermi energy the charge
changes abruptly in a unity. We show that this behavior closely relates with
discontinuities in the conductance predicted for interacting quantum dot
systems.
