disease overview

Normal Cell

Non-affected cell with I2S enzymes and GAGs within the lysosomes.
Cell affected by I2S deficiency with less I2S enzymes and more GAGs in the lysosomes.

In a non-affected cell, GAGs are naturally produced as waste materials and are then broken down by the I2S enzyme within the lysosomes.

Cell affected by I2S enzyme deficiency

I2S enzyme deficiency
Nucleus Enzyme GAG buildup In cells affected by Hunter syndrome, as the I2S enzyme is deficient or missing, the GAGs cannot be broken down and they build up in the lysosomes of cells throughout the body. This accumulation of GAGs interferes with the way different organs in the body function and leads to a number of symptoms. As the GAG buildup continues throughout a child’s early life, these symptoms become more visible and reflect the progressive nature of Hunter syndrome.