Enables N-acetylglucosamine-6-sulfatase activity; glycosaminoglycan binding activity; and sulfate binding activity. Involved in keratan sulfate catabolic process. Located in lysosome. Human ortholog(s) of this gene implicated in mucopolysaccharidosis III and mucopolysaccharidosis type IIID. Orthologous to human GNS (glucosamine (N-acetyl)-6-sulfatase). [provided by Alliance of Genome Resources, Apr 2022]