Interview Study of Adult and Child Patients and Parents of Children With Swelling Due to Nephrotic Syndrome.

Criteria for the Observer Reported Outcomes (ObsRO) cohort of the study:

Inclusion Criteria:

1. Parents/guardians must be able to read and understand English;
2. Parents/guardians must be caring for a child (ages 2-11.999) with a medically documented diagnosis of idiopathic (primary) Nephrotic Syndrome (NS) or primary or monogenic NS associated kidney disease. Populations with Primary NS Conditions: Focal segmental glomerulosclerosis (FSGS), Minimal Change Disease (MCD), Immunoglobulin M (IgM) Nephropathy, Membranous Nephropathy (MN), and childhood - onset nephrotic syndrome not biopsied;
3. The child must have a current NS-associated edema
4. The child must have native kidney function
5. Parents/guardians must provide informed consent.

Exclusion Criteria:

1\. Index case with dialysis dependence throughout the 3-month pre-enrollment period

Criteria for the Patient Reported Outcomes (PRO) cohort of the study:

Inclusion Criteria:

1. ≥8 years of age
2. Able to read and understand English
3. Primary (idiopathic) kidney disease that causes NS or monogenic NS associated kidney disease.

   i. Populations with Primary Nephrotic Syndrome (NS) Conditions include: FSGS, MCD, IgM nephropathy, MN, and childhood - onset nephrotic syndrome not biopsied
4. Current NS-associated edema
5. Kidney function with most recent estimated Glomerular Filtration Rate (eGFR) \> 25 ml/min/1.73m2
6. Informed Consent: For patients ≥8 to \<18 years of age: a parent or legal guardian provide informed consent and the patient must provide assent. Patients ≥18 years of age must provide informed consent.

Exclusion Criteria:

1. Native kidney disease participant with dialysis dependence during the 3-month pre-enrollment period
2. Co-existing significant chronic or severe acute health condition that has the potential to influence how the participant feels or functions as related to fluid overload in NS