A 3-day-old neonate presents with episodes of jitteriness and seizures. Blood glucose is 30 mg/dL. The neonate is the large-for-gestational-age (LGA) infant of a gestational diabetic mother. Despite correction with IV glucose, hypoglycemia recurs. Serum insulin is elevated at the time of hypoglycemia. Which of the following is the most likely diagnosis?
- A Congenital hyperinsulinism due to KATP channel defect
- B Beckwith-Wiedemann syndrome
- C Transient hyperinsulinism of infancy ✓
- D Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) due to SUR1 mutation
Explanation
Hyperinsulinism in an LGA infant of a diabetic mother is the classic presentation of transient hyperinsulinism of infancy. Maternal hyperglycemia causes fetal beta-cell hyperplasia, which persists transiently after birth; this usually resolves within days to weeks. Congenital hyperinsulinism (KATP channel defect/SUR1 mutation) presents similarly but persists beyond the neonatal period and is not associated with maternal diabetes or LGA status. Beckwith-Wiedemann syndrome causes macrosomia, macroglossia, omphalocele, and ear creases, and features organomegaly; while hypoglycemia occurs, the clinical scenario here points to the diabetic mother etiology rather than a syndrome.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.