Hunter Syndrome: Clinical Case of Early Diagnostics

Abstract

Background. This clinical case of orphan disease can be interesting for its early diagnostics which is essential for timely specific therapy and sufficient dynamic observation. Clinical case description. Mucopolysaccharidosis type II (Hunter syndrome) diagnosis at the age of 12 months was based on common external manifestations, recurrent otitis and isolated osteoarticular system lesions without any other systems decompensations. The awareness of doctors about the disease criteria and its diagnostics algorithm, as well as the availability of laboratory testing on lysosomal enzyme iduronate-2-sulfatase (I2S) activity are crucial for early diagnosis. The patient has undergone molecular genetic testing: mutations in the IDS gene encoding iduronate-2-sulfatase were revealed. The enzyme replacement therapy with idursulfase according to the protocol has been started. Patient’s condition has improved on the therapy (after 4 months of the therapy): stable neuropsychic development (no delay), increased large joints flexibility, reduced hepatosplenomegaly, and no hearing loss. Conclusion. Timely diagnostics of mucopolysaccharidosis allows to start enzyme replacement therapy early and significantly ease the disease course despite the severe congenital defect in the glycosaminoglycans metabolism.