부산대학교 도서관

· Expansion of the phenotypic spectrum of neuromuscular glycogen storage disease type IV (GSD IV). · Antenatal neuromuscular GSD IV is not unequivocally lethal in the neonatal period. · Neuromuscular GSD IV and can mimic a congenital myopathy and cause limb girdle weakness. · Diagnosis of GSD IV is possible without polyglucosan bodies detected on muscle biopsy. Glycogen storage disease type IV (GSD IV) is caused by mutations in the glycogen branching enzyme 1 (GBE1) gene and is characterized by accumulation of polyglucosan bodies in liver, muscle and other tissues. We report three cases with neuromuscular forms of GSD IV, none of whom had polyglucosan bodies on muscle biopsy. The first case had no neonatal problems and presented with delayed walking. The other cases presented at birth: one with arthrogryposis, hypotonia, and respiratory distress, the other with talipes and feeding problems. All developed a similar pattern of axial weakness, proximal upper limb weakness and scapular winging, and much milder proximal lower limb weakness. Our cases expand the phenotypic spectrum of neuromuscular GSD IV, highlight that congenital myopathy and limb girdle weakness can be caused by mutations in GBE1, and emphasize that GSD IV should be considered even in the absence of characteristic polyglucosan bodies on muscle biopsy. [ABSTRACT FROM AUTHOR]