Down syndrome (DS) is associated with a high prevalence of congenital heart, gastrointestinal, and endocrine anomalies, as well as a heightened risk for kidney and urinary tract abnormalities. The renal anomalies occur in up to 3.2% of DS cases at birth-four to five times higher than in the general population. Despite this, current DS management guidelines lack routine kidney evaluations, even though risk factors like neonatal acute kidney injury, renal hypoplasia and obesity may predispose DS children to chronic kidney disease (CKD). In a cross-sectional study, we analysed kidney size and function in 54 DS children. Results revealed that 25% of patients exhibited renal hypoplasia, 26% had an estimated glomerular filtration rate (eGFR) below 90 mL/min/1.73 m