This study will evaluate the safety of multiple biweekly intravenous doses of Replagal over 26 weeks in 25 children with Fabry disease and the way in which that agent can improve the health of this patient population. Fabry disease is a genetic disorder inherited as an X-linked recessive trait. It causes a deficiency in the enzyme alpha galactosidase, which normally breaks down a lipid, or fatty substance, called ceramidetrihexosidase, a building block in all cells of the body.