Background and Aims Neonatal Dabetes Mellitus(NDM) is a rare(1/400,000 newborns) but potentially devastating condition. It has been defined as insulin-sensitive hyperglycemia that is diagnosed within the first six months of life and can be either transient(TNDM) or permanent(PNDM). PNDM has been linked to mutations in several different genes. TNDM is associated with defects in an imprinted region of the paternally derived chromosome 6. We describe a baby boy four months old diagnosed with PNDM.
Methods The patient was admitted to hospital with diabetic ketoacidosis(blood sugar>700mg/dl (>38.8mmol/l), pCO2 22mmHg, pO2 107mmHg, HCO3 12.1mmol/l). He had a preceding fortnight history of polyuria, polydipsia, lethargy and vomiting the last few days before admission. Clinically he was lethargic and dehydrated, with sunken fontanelle and eyes, reduced skin turgor, dry mucous membranes and had tachypnoea, ketotic breath. He was treated with intravenous fluids and insulin. Progressively he recovered and started feeding orally. He was discharged on daily insulin injections subcutaneously.
Results On admission glycated hemoglobin(HbA1c) was 5.8% (4.3–6.1%), anti-GAD autoantibodies 1.3(ratio>1.1 positive), IA2(tyrosine phosphatase antibodies) 1.2(< 8iu/ml), IAA(anti-insulin antibodies) 1.50(< 1.10 ratio), ICA(anti-islet antibodies) 0.5(< 1.00 ratio), EMA(anti-endomysial antibodies) negative. Past medical and family history were unremarkable. Genetic testing for PNDM failed to detect any mutations in the KCNJ11, ABCC8 and INS genes, as well as the testing for abnormalities in the chromosome 6q for TNDM.
Conclusions Genetic testing for NDM can identify PNDM in newborns helping the physician to select the most appropriate therapy. However, 40% of cases are currently without a molecular genetic diagnosis.