Polyglucosan Bodies in Placental Extravillious Trophoblast for the Diagnosis of Fatal Perinatal Neuromuscular Type Glycogen Storage Disease Type IV.

The fatal infantile neuromuscular type is the most severe form of glycogen storage disease type IV (GSD IV). We report a case of a 22-day-old female neonate born at 34 weeks gestation with polyhyramnios, fetal hydrops, and severe hypotonia. Placental examination revealed numerous periodic acid schiff-positive diastase-resistant polyglucosan bodies in the cytoplasm of extravillous trophoblast predominantly in the placental basal plate. Muscle biopsy and autopsy findings supported a diagnosis of neuromuscular-type glycogen storage disease type IV with extensive involvement of skeletal muscle, heart, and liver. The diagnosis was confirmed by molecular genetic testing. We could only find 1 prior report in the English literature that describes placental pathological changes. Our findings suggest that placental examination can be a useful adjunct for early diagnosis, as placentas are often received for pathological examination shortly after birth and usually before a diagnostic muscle biopsy can be performed. Pathologists need to be aware of characteristic placental features.