Background: Permanent neonatal diabetes (PND)with heterozygous mutations of KCNJ11, respond to treatment with sulphonylureas. We report a case of PND in a baby, and mother previously mis-diagnosed with Type 1 DM. Both were switched from insulin to oral sulphonylureas. We evaluate the response and evolution.
Case report: A male newborn at 37 weeks gestation, with a birthweight 2750 g (40thC) and length 48 cm (40thC), was admitted for glycemic monitoring. He presented with hyperglycemia in the first week, requiring insulin infusions during his first month 0.20.5 U/kg per day. Family history: Parents non-consanguineous. Mother on CSII diagnosed with Type I DM from the third month of life, having presented with severe ketoacidosis and dehydration. Currently: HbA1C: 9%. Initial laboratory evaluations in baby showed, blood glucose: 320 mg/dl, HbA1C:3.5%, no ketonuria, C-peptide:0.22 ng/ml, Insulin:3.2 mU/ml, with negative diabetes antibodies in mother and baby (Anti-GAD, Islet, insulin autoantibodies). Genetic testing undertaken simultaneously on both (at baby age 3.8 months) revealed heterozygous mutation in exon1 KCNJ11 (p.Arg201His,c.602G>A). Following gradual transition from insulin, at 3.8 months the patient was successfully shifted to sulphonylurea therapy, requiring at the beginning 0.45 mg/kg per day, decreasing to 0.2 mg/kg per day from the 4th month until 2.6 years, requiring 0.15 mg/kg per day currently. We evaluated pancreatic insulin reserve and glycemic control prior to transition, HbA1c, fasting insulin and c-peptide over successive years. As result, the glycemic control and the pancreatic reserve were improved in both. Evolution HbA1c: 5.25.7% throughout the treatment time. Two years since starting sulphonylureas: fasting insulin 3.9 mU/ml and C-peptide 0.7 ng/ml; 3 years since starting; fasting insulin: 10 mU/ml and C-peptide: 2.88 ng/ml.
Conclusion: Although the clinical onset of patients with mutations in Kir6.2 is typically described from the first month of life, our case suggests that the blood glucose levels are already affected from birth. This case shows that earlier treatment with sulphonylureas improves pancreatic reserve increasing the c-peptide leading to lower doses being required. We will re-evaluate the diagnosis of patients with early onset Type 1 DM.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology