KATP channel mutations in infants with permanent diabetes diagnosed after 6 months of life

Abstract

Background/objective: Mutations in the K(ATP) channel genes are the commonest cause of permanent neonatal diabetes. Most patients obtain optimal glycemic control on sulfonylurea treatment. Genetic testing is currently recommended for all infants diagnosed before 6 months of age. We aimed to explore the prevalence of K(ATP) channel diabetes in infants presenting between 6 and 12 months.

Methods: The KCNJ11 and ABCC8 genes were sequenced in 115 infants with permanent diabetes diagnosed between 6 and 12 months and in 405 patients presenting before 6 months.

Results: Mutations in either gene were identified in 197 patients diagnosed before 6 months (48.6%), three infants diagnosed between 6 and 9 months (4.2%) and none of those diagnosed after 9 months. Two patients diagnosed after 6 months were successfully transferred from insulin to sulfonylureas.

Conclusion: K(ATP) channel mutations are an uncommon cause of diabetes in infants presenting after 6 months. However, given the potential clinical benefit from identifying a K(ATP) channel mutation, we recommend that K(ATP) mutation testing should be routinely extended to infants diagnosed up to 9 months.