Hunter syndrome is a rare, inherited disorder in which the body does not properly digest (break down) sugar molecules in the body. When these molecules build up in organs and tissues over time, they can cause damage that affects physical and mental development and abilities. The disorder almost always occurs in boys. Apr 16, · Hunter syndrome falls in a group of lysosomal storage diseases known as mucopolysaccharidoses of which it is also known as mucopolysaccharidosis type II (MPS II). It is a rare X linked recessive disorder that is found exclusively in males, although sporadic female cases are also found. Hunter syndrome occurs in 1 in , to 1 in , males.