Serum Creatinine Levels in Children With Down Syndrome: A Single‐Centre Retrospective Study in Ireland

ABSTRACT Aim To assess the proportion of children with Down syndrome (DS) with creatinine levels above standard paediatric reference ranges in a single‐centre Irish outpatient cohort. Methods We performed a retrospective cross‐sectional study of children aged 0–16 years attending the DS Clinic at Children's Health Ireland, Tallaght, between June 2022 and June 2024. Children with known renal disease and acute results were excluded. Creatinine levels were analysed using age‐ and sex‐specific reference ranges. The proportion with creatinine above the upper reference limit was compared with the expected proportion of 2.5% using a one‐sided exact binomial test. Estimated glomerular filtration rate (eGFR) was calculated using the bedside Schwartz equation, where height was available. Results A total of 194 patients were included. Among them, 52 (26.8%) had creatinine levels above the upper reference limit ( p < 0.0001). Additionally, 42 (21.6%) had persistently elevated creatinine ( p < 0.0001). Height was available for 124 children. Of those, 42 (34%) had an eGFR < 90 mL/min/1.73 m 2 and 1 (0.8%) had an eGFR < 60 mL/min/1.73 m 2 . Conclusion Children with DS in this Irish clinic frequently had creatinine levels above standard reference ranges. Further studies are required to clarify the clinical significance of these findings.