Switching from insulin to oral sulfonylureas in patients with permanent neonatal diabetes – case report

Introduction. Neonatal diabetes is a rare disease and it is frequently caused by a mutation in the KCNJ11 gene, which encodes the Kir6.2 subunit of the ATP-sensitive potassium channel. If the neonatal diabetes is associated with epilepsy and developmental delay, then the diagnosis is of DEND syndrome (developmental delay, epilepsy and neonatal diabetes).

Aim. To determine which are the best methods of diagnosis and treatment for a child with neonatal diabetes.

Methods and results. We present the case of a 9 years old girl, diagnosed with neonatal diabetes at age 3 months, who was first admitted to our clinic in December 2015 for frequent episodes of hyperglycemia at home and absence seizure lasting 2-4 minutes, suggesting minor epilepsy. The patient was treated with insulin from the moment of diagnosis until age 9 months, then with oral antidiabetic agents until January 2015, when she started again the insulin therapy in the context of persistent hyperglycemia and a level of glycated hemoglobin (HbA1c) of 10.6%. Her physical examination revealed height and weight according to age, with stable vital signs. The laboratory findings were all unremarkable, except for blood glucose values of 200-300 mg/dl and HbA1c level of 10.3%. The patient also had moderate mental delay, with an IQ of 66. The genetic testing for neonatal diabetes revealed a heterozygous mutation in KCNJ11 gene, so the diagnosis was of DEND syndrome. We initiated the treatment with glibenclamide 3.5 mg, 8 tablets/day and we recommended cognitive functions’ stimulation with exercises and reading 4-5 hours/day.

Conclusions. The genetic testing for the identification of a mutation in KCNJ11 gene has an important impact on the therapeutic approach in children with neonatal diabetes, as there is the possibility to replace the insulin therapy with antidiabetic oral agents, therefore improving the quality of life and possibly the epilepsy seizures.