RESUMO
OBJECTIVE: To report a case of Persistent Hyperinsulinemic Hypoglycemia in twins which is a situation not yet reported in the literature. METHODS: Report of seizures in identical twins, from consanguineous parents, with persistent hypoglycemia as cause of the seizures. Laboratory tests, performed for etiological investigation of the hypoglycemia, included thyroid hormones (T4/TSH), insulin, cortisol, growth hormone, stimulation test with glucagon (to evaluate the insulin/glucose relation), and histopathological study of the pancreas. RESULTS: Laboratorial investigation revealed a persistent hypoglycemia with hyperinsulinism which were confirmed with the stimulation test with glucagon. The histopathological exam showed a persistence of first generation pancreatic islet, confirming the diagnosis of Persistent Hyperinsulinemic Hypoglycemia in Infancy (the new denomination of Nesidioblastosis). CONCLUSION: Although rare, this condition must be early suspected early in the evaluation of hypoglycemia of the young infant, even out of the neonatal period, specially if the parents are consanguineous. The adequate therapy must be quickly initiated in order to prevent neurological damage.