Early brain atrophy in persistent hyperinsulinemic hypoglycemia of infancy.

We present two siblings with persistent hyperinsulinemic hypoglycemia of infancy, accelerated intrauterine growth and early neonatal brain atrophy. Fetal plasma glucose and insulin levels in the second sibling revealed normoglycemia despite hyperinsulinemia. The absence of intrauterine hypoglycemia suggests that the brain damage is not secondary to hypoglycemia and other etiologies must be considered.