We report here the course and outcomes of 18-month enzyme replacement therapy in two 43 and 41-year-old brothers with Fabry disease. At 18 months of recombinant alpha-galactosidase A (Fabrazyme) infusions, we observed in the older patient: weight gain, decreased proteinuria (from 4 to 1.5 g/d), stabilization of creatinine clearance, much lower frequency and intensity of angina, and in the younger brother: weight gain, stabilization of creatinine clearance and proteinuria, prolongation of PQ interval and improvement of hearing. However, neurologic manifestations deteriorated over treatment period in both patients. No serious infusion-related side effects were observed.