Renal dysfunction is a major complication in hemizygous males with Fabry disease. This often results in end-stage renal failure (ESRF), requiring dialysis or transplantation, on average 10 years after the start of renal impairment. ESRF usually occurs between 40 and 50 years of age, but may occur much earlier. Although progression of renal disease can be rapid, it is variable and may depend on whether there is residual alpha-galactosidase enzyme activity and on environmental or genetic factors. Significant renal disease is much less common in women carriers of the disease. However, renal changes do occur, which may progress to ESRF as in male patients.