ESPE Abstracts

Background: Neonatal diabetes (ND) is a rare condition (1:160.000-260.000 live births) associated with diabetes onset within the first 6 months of life. It can be permanent (PNDM) or transient (TNDM), and several genes can be implicated in both, namely KCNJ11. Clinical phenotypes usually correlate to the causal gene. KCNJ11 mutations are usually associated with PNDM whilst the most frequent cause of TNDM is disordered imprinting in the 6q24 locus.

Objective and hypotheses: To report a case with uncommon features.

Method: Case report.

Results: A male infant (DOB:04.04.2013), second child of a consanguineous couple, was born at the term of an uneventful pregnancy by vaginal delivery, adequate for gestational age, with Apgar 5/9/10. Minor dismorphies, hypotony and feeding difficulties were noticed. He was readmitted on the 11th day of life because of failure to thrive and clinical deterioration; 6 days later, severe diabetic ketoacidosis was diagnosed (pH 7.0, glucose 1421 mg/dl, Na⁺172 mmol/l). Glycemic control was difficult to achieve under i.v. and subsequently s.c. insulin. He was transferred to our level III center at 2 months of age and started on continuous s.c. insulin infusion with improved glycemic control. Neurologically, he maintained axial hypotony and poor-for-age interaction, without seizures. Electroencephalogram and intracraneal ultrasound were normal. Insulin requirements progressively diminished and he was discarded without insulin 1 month afterwards. Since then, he has remained normoglycemic with peaks of glycemia during infectious episodes. A KCNJ11 mutation was identified both on the infant and his mother (c.679G>Ap.E227K).

Conclusion: The association of ND with developmental delay, without seizures, raised the hypothesis of intermediate DEND syndrome. KCNJ11 mutations only cause TNDM in 10% of cases. To our knowledge this is the first reported case of TNDM associated with DEND features. Due to the elevated risk for diabetes recurrence, close long-term surveillance is mandatory.