 Participants who are diagnosed with ADPKD between the ages of 15 and 45 with risk factors 23 of the study population or without risk factors 13 of the study populationfor progression to ESRD with relatively normal renal function were be eligible for recruitment into the CRISP I study. The objective of the recruitment process was to identify ADPKD participants with the appropriate level of renal function who are either at high or low risk for progression to ESRD, who will be available for the entire follow-up period and who are likely to be compliant with the study protocols and visit schedules. 