Mucopolysaccharidosis type VI (MPS VI, Maroteaux-Lamy syndrome, MPS VI, OMIM 253200) is caused by deficient activity of N-acetylgalactosamine-4-sulphatase (4-sulphatase, arylsulphatase B, ARSB, EC 3.1.6.12) [1]. Here, ARSB is linked to mucopolysaccharidosis type 6.