Neonatal Congenital Hyperinsulinism: A Case-Based Contribution to the Understanding of a Rare Disorder

Abstract

Congenital hyperinsulinism (CHI) is a rare but significant cause of persistent neonatal hypoglycemia (NH), associated with a high risk of neurological complications if not promptly treated. This condition is characterized by inappropriate insulin secretion, often of genetic origin, independent of blood glucose levels. We report the case of a male macrosomic newborn admitted on the second day of life for respiratory distress, generalized seizures, and severe hypoglycemia (1.4 mmol/L) unresponsive to intravenous glucose therapy. Laboratory investigations revealed elevated insulin and C-peptide levels, absence of ketone bodies, and a positive response to the glucagon stimulation test. Echocardiography showed hypertrophic cardiomyopathy without functional impairment. Due to limited resources, neither [18F]-fluoro-L-DOPA PET imaging nor genetic testing could be performed. Treatment with a combination of diazoxide and octreotide led to partial improvement, but the clinical course was unfavorable, with the infant dying at four months of age due to sepsis. This case highlights the diagnostic and therapeutic challenges of CHI in resource-limited settings. Through this clinical observation and a review of the literature, we emphasize the importance of a rigorous diagnostic approach and early, multidisciplinary, and tailored management to reduce the morbidity and mortality associated with this rare condition.