Peritoneal Dialysis (PD) is a technique for treating kidney failure where fluid is instilled into the body's peritoneal cavity. Fluid and solutes travel across the peritoneal membrane, and the function of this membrane is critical to successful PD. Studies have shown that certain demographic and clinical variables explain a very small part of the variability in baseline function. This study will further explore the common genetic variants that determine the baseline peritoneal membrane function in patients starting treatment with PD and change in function upon treatment .