what is hunter syndrome

Hunter syndrome, also known as mucopolysaccharidosis type II, is a rare genetic disorder that primarily occurs in boys. It is caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (I2S), which leads to the accumulation of large sugar molecules called glycosaminoglycans (GAGs) in body tissues. This accumulation can cause damage to physical and mental development over time. Some common symptoms of Hunter syndrome include skeletal abnormalities, hearing loss, retinal degeneration, and an enlarged liver and spleen. Healthcare providers classify Hunter syndrome into severe and mild types, with the severe type progressing faster and involving impaired intellectual abilities. Hunter syndrome is one of a group of diseases called mucopolysaccharidoses. It is very uncommon, and it almost always occurs in children assigned male at birth. Providers diagnose it in roughly 1 out of every 100,000 to 170,000 children assigned male at birth.