Involved in the degradation of heparan sulfate. Hydrolysis of terminal non-reducing N-acetyl-D-glucosamine residues in N-acetyl-alpha-D-glucosaminides. Monomer and homodimer. Liver, ovary, peripheral blood leukocytes, testis, prostate, spleen, colon, lung, placenta and kidney. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the glycosyl hydrolase 89 family. A MPS3B mutation at position 100 was erroneously reported (PubMed:9950362) as an amino acid change from Arg to His. The right amino acid change is from His to Arg.