First case of neonatal diabetes with KCNJ11 Q52R mutation successfully switched from insulin to sulphonylurea treatment

In this report, we present the first known case of intermediate developmental delay, epilepsy and permanent neonatal diabetes (DEND) syndrome caused by a Q52R mutation in the KCNJ11 gene who was successfully switched (at age 1.3 years) to sulphonylurea monotherapy, namely glibenclamide. The most recent evaluation, after 2 years, showed a glycated hemoglobin level of 6.0% (42 mmol/mol). This mutation is so severe that none of the previously reported four cases were able to switch from insulin to sulphonylurea monotherapy. The Q52R mutation seems to have a chance of positive response to glibenclamide administered every 3–6 h instead of the classical 8–12 h, in doses around or above 2.5 mg/kg/day.