N-Acetylglucosamine-6-Sulfatase is a member of the Sulfatase family. N-Acetylglucosamine-6-Sulfatase is required for the lysosomal degradation of the Glycosaminoglycans (GAG) Heparan Sulfate and Keratan Sulfate. N-Acetylglucosamine-6-Sulfatase hydrolyzes the 6-Sulfate groups of the N-Acetyl-D-Glucosamine 6-Sulfate units of Heparan Sulfate and Keratan Sulfate. N-Acetylglucosamine-6-Sulfatase binds 1 Calcium ion per subunit. N-Acetylglucosamine-6-Sulfatase deficiency are the cause of Mucopolysaccharidosis Type 3D (MPS3D), an inborn error leading to lysosomal accumulation of heparan sulfate. MPS3D has profound mental deterioration, hyperactivity, and relatively mild somatic manifestations.