[Clinical features and acid alpha-glucosidase gene mutation in 7 Chinese patients with glycogen storage disease type II].

To explore the clinical features and acid alpha-glucosidase (GAA) gene mutations of Chinese patients with glycogen storage disease typeII(GSDII).Seven patients with GSDII were diagnosed by muscle pathology examination at Department of Neurology, Peking University First Hospital from 2003 to 2011. One patient with infant-onset presented development retardation, generalized muscle weakness, dyspnea, cardiomegaly and hepatomegaly. Six cases were of late-onset ranging from 1 to 29 years. Their main clinical features included progressive muscle weakness. Two patients developed respiratory insufficiency. Increased serum creatine kinase was detected in all of them. Electromyography studies showed myopathic (n = 5) and neuropathic (n = 1) changes. Muscle biopsies showed basophilic vacuoles in muscle fibers containing a large amounts of glycogen on electron microscopy. GAA gene mutation was detected by direct sequencing of polymerase chain reaction (PCR) product. Novel mutations were screened in 100 normal controls.GAA gene mutations were found in all of them, including 10 point mutations and 1 frameshift deletion. Six mutations (p. P361L, p. P266S, p.R437C, p.R600C, p.W746S and p.W746*) have been reported before. And five novel mutations (p.R168Q, p.R168P, p.E521V, p.R594H and c.827_845del) were found in this study. None of these novel mutations were found in 100 normal controls except for p.R168Q mutation in two normal controls. p. P361L and p.W746* were detected in two unrelated GSDII patients while other mutations were carried by only one patient.In our study, we found several novel GAA mutations in Chinese patients with GSDII. No hot spot mutation of GAA gene existed in our patient group. However, p. P266S, p. P361L and p.R437C might be associated with late-onset GSDII.