Chronic Kidney Disease in Children Prospective Cohort Study (CKiD)

Inclusion Criteria:

• Age between 1 and 16 years (before 17th birthday) for Cohorts 1 and 2; age between 6months and 16 years (before 17th birthday) for Cohort 3; age between 16 to 22 years (before 23rd birthday) for Cohort 4 and regularly seen by pediatric nephrologistprior to enrollment

• Estimated (based on SCr) Schwartz GFR between 30 and 90 ml/min|1.73m2 for Cohort 1OR an estimated GFR between 45 and 90 ml/min|1.73m2 based on the updated Schwartzformula for Cohort 2; an estimated GFR ≤60 based on the CKiD Under 25 estimatingequation (U25eGFR) OR KRT experience (dialysis or transplant) for Cohort 4

• Willingness and ability to provide informed consent and assent

• For Cohort 3, children with non-glomerular diagnosis and duration of kidney diseaseless than 5 years will be enrolled.

Exclusion Criteria:

• Solid organ (other than kidney), bone marrow or stem cell transplantation

• Cancer diagnosis and receiving treatment or within 12 months post completion oftreatment

• HIV diagnosis and receiving treatment or within 12 months post completion oftreatment

• Current pregnancy or pregnancy within past twelve months

• Inability to complete major data collection procedures

• Not fluent in English or Spanish

• Plans to move out of area of any participating CKiD site (families can betransferred to another CKiD site if the family moves)

• Existing moderate to severe congenital structural heart disease

• Genetic syndromes involving the central nervous system (e.g., Downs syndrome)

• History of severe to profound intellectual disability (i.e., Intelligence Quotient (IQ)<40, significant impairment in adaptive function and/or inability toindependently execute self-care skills)

• For cohort 3, children who are expected to receive renal replacement therapy within 6 months of date of enrollment will not be recruited