Mucopolysaccharidosis Type II in Young Brothers: Three Cases and a Review of the Literature

Mucopolysaccharidosis (MPS) are progressive deposition diseases that present the accumulation of glycosaminoglycans (GAGs) into various tissues and organs, resulted by the deficiency of enzymes that degrade proteoglycans. There are seven types of MPS (I, II, III, IV, VI, VII, and IX), according to the missing enzyme. This study proposes to describe three brothers with MPS followed up in the pediatric otorhinolaryngology outpatient clinic of the ENT Hospital-Banco de Olhos de Sorocaba (BOS), diagnosed with MPS II (Hunter syndrome). The aim of this paper is to show the importance of the knowledge of MPS by otorhinolaryngologists. MPS II is caused by the lack of iduronate 2-sulfatase enzyme which leads to a lysosomal storage of dermatan and heparan sulfate. It is a genetic disease with recessive character related to X, and its incidence is 1:170,000 live births. The syndrome diagnostic is made by clinical signs, specific laboratory tests, and genetic typification. Its clinical manifestation is heterogeneous, since an attenuated presentation with late onset (patients reach adulthood) till a severe form beginning around 3 years old, with a life expectancy is limited to the second decade of life. This illness affects the musculoskeletal, digestive, cardiovascular, respiratory, and central nervous systems. Otorhinolaryngological signs and symptoms include hypoacusia, otorrhea, recurrent otitis, pharyngeal and palatine tonsils enlargement, recurrent sinusitis, speech disorders, snoring, sleep apnea, mouth breathing, and nasal obstruction. That is the reason why ENT must be familiar to MPS to contribute with the early diagnosis and treatment.