Congenital Hyperinsulinism

Background: Congenital hyperinsulinism (CHI) is a rare condition that usually presents in the newborn period. It is characterized by hypoketotic hypoglycemia due to excessive insulin secretion. We describe below a case of CHI due to a paternally inherited mutation of the ABCC8 gene and the challenges in its management. Clinical Description: A term female appropriate for gestational age baby with an uneventful antenatal period and delivery presented at 46 h of life with fever, decreased oral acceptance, lethargy, and hypoglycemic seizures. On examination, the baby was febrile but hemodynamically stable with no other clinical evidence of sepsis. Management: Child had recurrent episodes of hypoglycemia and required a glucose infusion rate of 12 mg/kg/min for maintaining euglycemia. The baby required diazoxide and octreotide for maintaining euglycemia. The hypoglycemia was nonketotic and associated with hyperinsulinism. 18-fluoro-dihydroxyphenylalanine positron emission tomography-computerized tomography scan showed diffuse uptake in the pancreas suggestive of diffuse hyperinsulinism. However, genetic testing showed heterozygous mutation for paternally transmitted pathogenic ABCC8 splicing variant. The child was stabilized and discharged on oral diazoxide and long-acting octreotide. Conclusion: CHI is an important cause of persistent hypoglycemia in neonates. Early diagnosis and management are important to prevent long-term sequalae. Establishing a correct molecular diagnosis is essential to decide about appropriate line of management (surgical/conservative) and provide genetic counseling to the family.