On Oct. 25, 1996, the first gene therapy trial for patients with Hunter syndrome was begun at the University of Minnesota, led by led by pediatrician Chester Whitley from the UM, Hospital.

Hunter syndrome is also known as MPS II. Children with this condition have an abnormal accumulation of complex sugars in their cells, which affects many systems in their bodies. Hunter syndrome primarily occurs in boys and is one of about 50 diseases classified as lysosomal storage disorders (LSD).