Neonatal Diabetes in Ireland over the Past 19 Years: Clinical Presentation, Management, Genetics, and Outcomes

Neonatal diabetes mellitus (NDM) is a rare monogenic form of diabetes presenting before 6 months of age. It may be permanent (PNDM) or transient (TNDM). Individuals with K_ATP channel variants may respond to oral sulphonylurea instead of insulin. The study aimed to review the presentation, genotype, phenotype, management, and outcomes of patients diagnosed with NDM in Ireland over 19 years.

Data on Irish NDM cases from 2006 to 2024 were collated through paediatric endocrinologists nationally and electronic databases. Analyses were performed using SPSS, with ethical approval obtained.

Nineteen cases were identified: twelve PNDM and seven TNDM. Age at diagnosis ranged from 1 day to 11 months. Among PNDM cases, KCNJ11 (n = 6), EIF2AK3 (n = 3) and INS (n = 1) variants were identified, while two lacked a genetic diagnosis. Six TNDM cases had 6q24 methylation defects, and one had an ABCC8 variant. Genetic diagnosis informed familial risk and prompted changes to a parent's medical management. Sulphonylurea therapy was most effective when initiated early.

This national case series highlights the genetic and phenotypic spectrum of NDM in Ireland. Early genetic diagnosis enables precision therapy, with timely sulphonylurea initiation improving outcomes in K_ATP-related NDM.