Inclusion Criteria:

• Diagnosis of MCD, FSGS, MN, or IgAN on first diagnostic kidney biopsy, as per specified pathology definitions.
• First diagnostic kidney biopsy within 5 years of study enrollment.
• Access to first kidney biopsy report and/or slides.
• All ages.
• Willingness to comply with study requirements, including intention to fully participate in protocol-specified follow-up at a clinical study site.
• Informed consent and, where age appropriate, informed assent.

Exclusion Criteria:

• ESKD, defined as chronic dialysis or kidney transplant.
• Institutionalized patient.
• Solid organ or bone marrow transplant recipient at time of first kidney biopsy.
• Diagnosis of any of the following at the time of first diagnostic kidney biopsy:
  • Diabetes mellitus (except gestational or diet controlled);
  • Histopathologic findings of diabetic glomerulosclerosis;
  • Systemic lupus erythematosus;
  • HIV infection;
  • Active malignancy, except for non-melanoma skin cancer;
  • Active Hepatitis B or C infection, defined as positive viral load.

Eligibility last updated 6/24/22. Questions regarding updates should be directed to the study team contact.