  We present magnetotransport data on the ferrimagnet GdMn$_6$Sn$_6$. From the
temperature dependent data we are able to extract a large instrinsic
contribution to the anomalous Hall effect $\sigma_{xz}^{int} \sim$ 32
$\Omega^{-1}cm^{-1}$ and $\sigma_{xy}^{int} \sim$ 223 $\Omega^{-1}cm^{-1}$,
which is comparable to values found in other systems also containing kagome
nets of transition metals. From our transport anisotropy, as well as our
density functional theory calculations, we argue that the system is
electronically best described as a three dimensional system. Thus, we show that
reduced dimensionality is not a strong requirement for obtaining large Berry
phase contributions to transport properties. In addition, the coexistence of
rare-earth and transition metal magnetism makes the hexagonal MgFe$_6$Ge$_6$
structure type a promising system to tune the electronic and magnetic
properties in future studies.
