With an exception of Dwyer et al. (2017), who reported data showing induction of postsynaptic proteins PSD-95 and GluA2 in the neurons of MPS IIIA mice [64], and Baldo et al. (2015), who showed increased levels of PSD-95 in the hippocampus of MPS I mice [59], the majority of studies agree on a decrease in the levels of pre- and postsynaptic proteins potentially leading to synaptic function impairments in neurological forms of LSD. The gene discussed is DLG4; the disease is mucopolysaccharidosis type 3A.