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.