  We study quantum transport in HgTe/HgCdTe quantum wells under the condition
that the chemical potential is located outside of the bandgap. We first analyze
symmetry properties of the effective Bernevig-Hughes-Zhang Hamiltonian and the
relevant symmetry-breaking perturbations. Based on this analysis, we overview
possible patterns of symmetry breaking that govern the quantum interference
(weak localization or weak antilocalization) correction to the conductivity in
two dimensional HgTe/HgCdTe samples. Further, we perform a microscopic
calculation of the quantum correction beyond the diffusion approximation.
Finally, the interference correction and the low-field magnetoresistance in a
quasi-one-dimensional geometry are analyzed.
