Sialidosis is a rare lysosomal storage disease caused by neuraminidase gene (NEU1) mutation and a deficiency of the enzyme neuraminidase. The aim of this study was to examine the sialidosis type 1 brain using volumetric magnetic resonance imaging (MRI), diffusion tensor imaging and functional MRI in comparison to 3 controls. The patients gene analysis identified compound heterozygous mutation in the NEU1 that is shown to be associated with the sialidosis type 1. In this very rarely seen case, we found volume changes in different brain structures. We found that subthalamic nucleus volumes were found to be smaller in the patient compared to the controls. Also, sialidosis type 1 had significantly smaller cerebellar volume compared with the control group. The case had higher mean diffusivity and lower fractional anisotropy values in the cerebellum and displayed abnormal functional connectivity.