RESUMEN
Glycogen storage disease (GSD) is a group of heterogeneous disorders of glycogen metabolism that results in abnormal storage of glycogen in multiple organs. Clinical manifestations of GSD vary according to the basic enzyme defect. Only types II, IV, V or VII of GSD have been known to manifest in the infantile period. Of the 11 types of GSD, the congenital subtype of GSD type IV is characterized by severe neonatal hypotonia, multiple contractures, polyhydramnios, and fetal hydrops. We report a case of a patient born at a gestational age of 34 weeks and 3 days with fetal hydrops, joint contractures, and akinesia. Muscle biopsy results were highly indicative of GSD. This is the first case of suspected GSD in Korea presenting as fetal hydrops. The possibility of other disorders associated with glycogen metabolism should be considered in fatal fetal hydrops patients with severe hypotonia and arthrogryposis, and aggressive investigations such as muscle biopsy should be performed for early diagnosis.