A case of Wiedemann-Beckwith syndrome (W-B syndrome) was reported. A female baby was born after 34 weeks of gestation, with a birth weight of 4254g. Prenatal echogram highly suspected W-B syndrome because of disproportionally large fetus and omphalocele. At birth, omphalocele and macroglossia were noted. Omphalocele was treated just immediately after birth. The baby showed severe hypoglycemia (10-20mg/dl) accompanying hyperinsulinemia (200μU/ml) , which was treatedby parenteral nutrition and she also showed persistent high levels of Alpha-fetoproteim (AFP), over 30×10^4nglml. Histological findings revealed nesidioblastosis and neonatal hepatitis. On the other hand, she developed hypertrophic obstructive cardiomyopathy (HOCM) approximately at age of 4 mouths which was treated with Ca antagonist successfully. We speculated that the HOCM corresponded to the prolonged hyperinsulinemia in the neonatal period. W-B syndrome is characterized by omphalocele, macroglossia and gigantism and it shows various clinical features and may present several critical problems, such as severe neonatal hypoglycemia. Therefore, perinatal intensive care is indispensable and longterm management is also necessary for this syndrome.
