Introduction: Beckwith–Wiedemann syndrome (BWS) is a congenital overgrowth disorder associated with dysregulation of genes on chromosome 11p15.5. Infants with BWS can present with hyperinsulinemic hypoglycemia. There are also distinctive clinical features including macrosomia, macroglossia and visceromegaly that may raise suspicion of this diagnosis. Case: A preterm female infant of 30 weeks gestation with a birth weight of 1.87 kg (97th centile) had recurrent hypoglycemia in the neonatal period, requiring escalation to a maximum glucose infusion rate of 17.6 mg/kg/min. Hypoglycemia only resolved after starting intravenous glucagon infusion. Critical sampling during hypoglycemia revealed serum insulin 3.9 µU/mL (3–25 µU/mL), serum ketone 0.2 mmol/L, cortisol 3,053 nmol/L and growth hormone 16.2 ng/mL. These findings supported the diagnosis of non-ketotic hyperinsulinemic hypoglycemia. She was commenced on oral diazoxide with resolution of hypoglycemia and discontinuation of glucagon. Examination at birth revealed macroglossia, hepatomegaly and ballotable kidneys. An initial US abdomen at birth revealed bilateral enlarged kidneys but normal liver. An initial chromosomal study revealed karyotype 46, XX. Over time, additional clinical features became evident fulfilling the diagnostic criteria for BWS, that is, polyhydramnios, large for gestational age, transient hypoglycemia, hyperinsulinism, macroglossia, hemihypertrophy, facial nevi, bilateral ear creases, hepatomegaly and ballotable kidney. A repeat US abdomen surveillance at 4 months old revealed a heterogeneous liver mass with marked vascularity, prompting a diagnosis of hepatic hemangioma. She was commenced on oral propranolol, with reduction in the size and vascularity of the liver hemangioma and decline in alpha-fetoprotein levels. Conclusion The clinical features of BWS may not be recognizable in a preterm baby in early neonatal period. Careful clinical examination should be done in a baby with persistent hyperinsulinemic hypoglycemia for underlying syndromal causes. US surveillance should also be carried out due to increased risk of hepatoblastoma or liver hemangioma in BWS, as was seen in this case.
Infant, Newborn ; Infant ; Beckwith-Wiedemann Syndrome ; Infant, Premature ; Hypoglycemia