Additional Study Information: This is a prospective cohort study, which means it is a study that follows over time a group ofsimilar individuals (cohorts) who differ with respect to certain factors under study, to determine howthose factors affect rates of a certain outcome. We will enroll about 2,400 adult and pediatric patients who have been diagnosed with one of four glomerular kidney diseases. In each case, the diagnosis must already be confirmed by biopsy. The glomerular kidney disease diagnoses include: IgAN (immunoglobulin A nephropathy), FSGS (focal segmental glmerulosclerosis), MN (membranous nephropathy), and MCD (minimal change disease). We plan to enroll 600 people in each category. Enrollment will occur across four Clinical Centers: Columbia, Midwest Pediatric Nephrology Consortium, University of North Carolina, and University of Pennsylvania. Patients who meet the enrollment criteria and want to join the study will be enrolled if they provide signed informed consent. Participation of minors requires consent from their parent or legal guardian. Total study duration is approximately 4 years. Study procedures will include collection of data as well as obtaining blood and urine specimens for laboratory analysis. Subjects will receive $25-50 per visit, to help defray the cost of travel and parking.