Detection by Urinary GAG Testing of Mucopolysaccharidosis Type II in an At-Risk Spanish Population

Hunter syndrome (Mucopolysaccharidosis type II) is an inherited lysosomal storage disorder with potentially severe degenerative consequences. Clinical diagnosis is not easy, although biochemical confirmation is straightforward, and sometimes patients are diagnosed at a late age. It is widely believed, for inborn errors of metabolism in general, that early diagnosis and management is of paramount importance for improving the prognosis of the disease. The objective of this study was to identify specific populations at risk of suffering from Hunter syndrome. Urine samples were obtained from children between the ages of 0 to 18, belonging to known risk groups of mucopolysaccharidosis (MPS) type II, for the semi-quantitative (GAG test) and quantitative determination of glycosaminoglycans (GAG). One case of Hunter syndrome was found among the 130 samples that were collected and analysed. This study supports the feasibility of early diagnosis and the usefulness of screening tests for MPS II in specific paediatric populations.