The deficiency in breaking down the lipid eventually causes that lipid to accumulate and injure cells. Problems in the blood vessels, kidneys, heart, and nerves are the result. The disease typically occurs in childhood or adolescence, with repeated episodes of severe pain in the extremities and other symptoms. There is no definitive treatment, but pain management is important in caring for patients with Fabry disease. Although it is not known exactly how lipid accumulation brings about such problems, studies of another lipid storage disorder, Gaucher's disease, have shown that the illness can be reversed if the lipid is removed when an appropriate enzyme, Replagal, is given intravenously. In this study, the gene response of the body's cells to Fabry disease will be described, as will any gene responses that change when the enzyme is used.