Background: Neonatal diabetes is a rare pathology occurring in around one in every 200 000400 000 live births. The most common cause of permanent neonatal diabetes (PNDM) is heterozygous activating mutations in the KCNJ11 gene encoding the pore-forming Kir6.2 subunit of the pancreatic β cell KATP channel.
Objective and hypotheses: To determine the dynamic of carbohydrate metabolism in family transferred from insulin to sulphonylureas (SU).
Method: We studied a family (mother and child) with PNDM diagnosed within the first 6 months of life. Carbohydrate metabolism was studied by iPro-2 monitoring, HbA1c, C-peptide, and insulin levels during 8 months of SU therapy. The KCNJ11 gene was sequenced by Sanger.
Results: A mutation in KCNJ11, R201H was identified in both patients. Transfer from insulin to SU tablets was done in child and mother at the age of 2 months and 28 years old accordingly. At the start of transfer process in child the daily dose of SU was divided into six doses (0.27 mg/kg per day), every feeding, but after 8 months of SU treatment frequency of dosing is reduced to four doses with decreasing of SU daily dose (0.17 mg/kg per day). The childs mother at 28 years old stopped insulin (45 units/day) and went on to SU in dose 15 mg/day. After 8 months of SU treatment HbA1c improved in both patients (in child 5.15 vs 13.9% and in mother 6.5 vs 8.9% accordingly). Daily monitoring (iPro-2) in child showed a marked reduction in the fluctuations as well as an overall lower level of glycaemic control (13.8 (2.626.6) mmol/l before SU treatment to 6.0 (3.310.2) mmol/l after). C-peptide level increased from 0.09 to 0.5 ng/ml in child and from 0.009 to 0.35 ng/ml in mother after 8 months of SU treatment accordingly.
Conclusion: Patients with diabetes presenting within the first 6 months of life should receive genetic testing to prescribe the pathogenetic treatment. Daily dose of SU in child during 8 months decreased by 37% on a background of improving of carbohydrate metabolism, HbA1c. A good response on SU treatment was observed even after 28 years of insulin therapy.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology