History of soy isoflavones for the treatment of mucopolysaccharide storage disease type 3. 1. firstly, soy isoflavones were found to reduce intracellular mucopolysaccharide levels at the cellular level as well as at the animal model level. 2. clinically, low doses (5-15 mg/kg/day) were firstly found to be effective in some patients, as evidenced by significant progress in hair color and intellectual and language development. 3. purified soy isoflavones were produced. 4. 4. A higher dose (150 mg/kg/day) of purified soy isoflavones was found to be safe for children; 5. storage disease type 3.