Rare Disease Day Jan. 28, 2017 My son Andrew has MPS 1 (Hurler Syndrome) MPS-Mucopolysaccharidoses- Hurlers (MPS1) is a genetic lysosomal storage disorder caused by the body’s inability to produce a specific enzyme (alpha l-iduronidaise). As cells in our body die, they are processed and digested by enzymes. MPS children are missing an enzyme essential to processing and digesting these dead cells. As a result, without Andrew's lifesaving bone marrow transplant, these cells would be stored and build up causing progressive damage throughout the body, including in the heart, bones, joints, respiratory system and central nervous system. In time, this leaves the child with various physical and neurological disabilities as well as severe mental impairment, loss of hearing and potential blindness. Hurler Syndrome is named after Gertrud Hurler who first described the condition in 1919.