ESPE Abstracts

Background and Purpose: Neonatal diabetes mellitus (NDM) is characterized by severe hyperglycaemia and is usually diagnosed in the first six months of life. Genetic diagnosis helps distinguish among its different causes and between transient and permanent forms, and the diagnosis has repercussions for the therapeutic approach and follow-up. We present three cases of NDM with different genetic abnormalities and different clinical courses.

Case 1: A 2-month-old boy was transferred to our hospital due to severe dehydration and circulatory failure. He was found to have diabetic ketoacidosis (DKA) and renal failure. Blood gas analysis revealed a pH of 7.17, pCO₂ of 30 mmHg, HCO3- of 11 mmol/L and BE of -16.1 mmol/L. The patient was started on continuous intravenous infusion of rapid-acting insulin and continuous haemodiafiltration for renal impairment. A heterozygous pathogenic variant was detected in the KCNJ11 gene (c. 679G>A, p. Glu227Lys) at 3 month of age. Insulin therapy was stopped after the introduction of glibenclamide. He is currently managed with peritoneal dialysis for renal failure.

Case 2: A female infant with macroglossia was born at 37 weeks of gestation, with a birth weight of 2,452 grams. She exhibited poor weight gain and a blood glucose level of 350 mg/dL on the 9th day of life. Insulin therapy was administered, but it was discontinued at 66 days of age because her blood glucose level had decreased. Methylation analysis of chromosome 6q24 revealed uniparental disomy. She is now 2 years old, her blood glucose level is within the normal range, and her growth and development are progressing normally.

Case 3: A 1-month-old infant was admitted to our hospital with DKA. The subcutaneous injection of rapid-acting insulin was required every time he breast fed. A heterozygous pathogenic variant was detected in the KCNJ11 gene (c. 602G>A, p. Arg201His) when he was 1 year old. Insulin therapy was stopped after glibenclamide was introduced at a dosage of 0.8 mg/kg/day. Now he is 19 years old and functioning normally.

Conclusion: Diabetes symptoms tend to be difficult to recognize in infants, which increases the risk of DKA. Infants who are “not acting right” should always be considered for blood glucose assessment. Additionally, we must consider a genetic study for patients with diabetes within the first six months of life.