However, children with chromosomal anomalies (RR 2.37, 95% CI 1.91–2.96), and specifically children with Down syndrome (RR 3.44, 95% CIs 2.70–4.37), Down syndrome with congenital heart defects (RR 3.86, 95% CIs 2.88–5.16) and Down syndrome without congenital heart defects (RR 2.78, 95% CIs 1.82–4.27), had a significantly increased risk of > 1 prescription for insulin/insulin analogues aged 0–9 years compared to reference children. The gene discussed is INS; the disease is Down syndrome.