ESPE Abstracts

Introduction: Neonatal diabetes mellitus (NDM) is a rare form of insulin-dependent monogenic diabetes mellitus (1/400,000 live births) diagnosed in the first six months of life. It can be either transient or permanent, with abnormalities in the parental chromosome 6q24 and with mutations in genes related to the ATP-sensitive potassium pump in the β-cell membrane respectively.

Aim: We describe a male infant, 2.5 months old, diagnosed with NDM and pancreatic hypoplasia.

Subjects and methods: The infant was admitted via the paediatric A&E with irritability, a two-week history of reduced feeding, and loose stools 6–10 times daily. His development was normal for age. He was the first child of healthy, unrelated parents, born at 40⁺³ weeks of gestation by caesarean section due to no progression of labour, IUGR, birth weight 2300 g. On examination he was alert, pale, with mild dehydration, vital signs normal. Laboratory testing showed hyperglycaemia without ketoacidosis, blood glucose 919 mg/dl (51 mmol/l), Na⁺121 mmol/l (NR 135–145 mmol/l), K⁺5.6 mmol/l (NR 3.5–5.1 mmol/l), pH 7.418, HCO3⁻ 25.3 mmol/l, BE 1.3 mmol/l), HbA₁c 13.6% (NR 4–6%) (125.1 mmol/mol, NR 20.2–42.1), insulin 1.6 μIU/l (2.6–24.9), C-peptide 0.449 ng/ml (NR 1.1–4.4), serum amylase 15 U/l (NR 28–100) and serum lipase 4 U/l (NR 13–60). Initially, he was treated with intravenous fluids and insulin, then with subcutaneous insulin. Diarhoea improved gradually, started gaining weight, he had normal stool on day eight after admission. Subsequently, he was started on CSII with synchronous continuous glucose monitoring (CGM). His latest HbA1c was 9.2% (77 mmol/mol).

Results: Antibodies to glutamic acid decarboxylase (anti-GAD) 0.1 (<10 U/ml) and insulin (IA2) 8.7 (<10 U/ml) were negative, pancreatic islet cell antibodies (ICA) were found marginally positive 1.6 U/ml (>1.05 U/ml positive). Fecal elastase was detected at very low levels (<15 grams/gr of faeces, NR >200) on two occasions. Abdominal ultrasound showed increased echogenicity of the pancreas which appeared to be hypoplastic for age; results confirmed by MRI of the abdomen. Genetic testing was negative for mutations in the KCNJ11, ABCC8 and INS genes.

Conclusions: The genetic causes of NDM in 40% of cases remain unknown. Congenital pancreatic hypoplasia may be responsible for NDM and deficiency of pancreatic exocrine function, therefore, requiring insulin therapy and pancreatic enzyme substitution.