Research progress of nervous system damage in Pompe disease / 中国当代儿科杂志

Pompe disease, also known as glycogen storage disease type Ⅱ, is a rare autosomal recessive disease. With the application of enzyme replacement therapy, more and more patients with Pompe disease can survive to adulthood, and nervous system-related clinical manifestations gradually emerge. Nervous system involvement seriously affects the quality of life of patients with Pompe disease, and a systematic understanding of the clinical manifestations, imaging features and pathological changes of nervous system injury in Pompe disease is of great significance for the early identification and intervention of Pompe disease. This article reviews the research progress of neurological damage in Pompe disease.

Clinical characteristics and gene analysis of one case of glycogen storage disease type Ⅱ / 中国基层医药

Objective:To investigate the key points of diagnosis and treatment of glycogen storage disease type Ⅱ(GSD Ⅱ).Methods:The clinical data of one child patient with GSD Ⅱ who received treatment in Hainan Children's Hospital on May 7, 2017 were retrospectively analyzed.Results:The child presented with atypical clinical manifestations, including pneumonia first, accompanied by muscle weakness and elevated muscle enzymes. Whole-genome sequencing showed that there were two heterozygous mutations in the acid alpha-glucosidase (GAA) gene, c.871C > T and c.1447G > A. The child was diagnosed with GSD Ⅱ.Conclusion:GSD Ⅱ has atypical clinical manifestations. It is easily misdiagnosed. Early whole-genome sequencing is helpful for the diagnosis of GSD Ⅱ.

Effect observation and literature review of enzyme replacement therapy in late-onset Pompe disease / 中华神经科杂志

Objective:To analyze the efficacy and safety of enzyme therapy in late-onset Pompe disease (LOPD) patients, so as to provide reference for the treatment and prognosis of LOPD.Methods:The effect of α-glucosidase (GAA) on a patient diagnosed with LOPD in the Affiliated Hospital of Jining Medical University was observed and analyzed. Besides, literature related to enzyme therapy in LOPD patients were searched in PubMed, Web of Science, Medline databases. Twenty-one studies containing clinical data from 910 LOPD patients related to enzyme therapy were finally included for analysis.Results:The patient developed muscle weakness since he was 16 years old. The GAA activity in peripheral blood was 0. Electromyography suggested myogenic lesions in both lower extremities. Compound heterozygous mutations of GAA gene were found by next- generation sequencing. Muscle biopsy revealed characteristic vacuolar changes. After eight years of diagnosis, the patient was given enzyme therapy for 18.5 months, 20 times in total. The symptoms of muscle weakness were slightly improved in the early stages of treatment without obvious adverse reactions. Most of the 910 LOPD patients were stabilized or had improved muscular and (or) respiratory function following treatment with GAA.Conclusion:GAA treatment is effective and well tolerated. In patients with advanced severe LOPD, enzyme replacement therapy remains effective even years after onset.

Clinical characteristics and genetic analysis of adult late-onset glycogen storage disease type II / 上海交通大学学报（医学版）

Objective: To investigate the clinical and genetic characteristics of adult late-onset glycogen storage disease type Ⅱ (GSD Ⅱ ). Methods: The clinical data, muscular magnetic resonance imaging (MRI) and muscle pathological characteristics of a patient with late-onset GSD Ⅱ were retrospectively analyzed and his family history was investigated. Peripheral blood DNAs of the proband and his father were extracted for genetic testing. Results: The proband presented progressive limb weakness for 7 years and short of breath after activities for 2 years. His parents were inbred, but he was the only one among the 18 members of 5 generations who had clinical phenotype. The blood creatine kinase moderately increased. The muscle MRI of both lower limbs showed that muscles were severely atrophied, and the fat component increased significantly. The pathological findings of muscle biopsy indicated vacuolar degeneration and increased activity of acid phosphatase. Gene sequencing confirmed that the pathogenicity was a homozygous mutation of acid α-glucosidase (GAA) gene c.1634C>T, and his father was a heterozygous mutation of c.1634C>T. Conclusion: Homozygous mutations of GAA gene c.1634C>T may lead to late-onset GSD Ⅱ.

Clinical and gene mutation analysis of three children with late-onset glycogen storage disease type Ⅱ with hypertrophic cardiomyopathy / 中华儿科杂志

Objective@#To investigate the clinical and laboratory features of three children with late-onset type Ⅱ glycogen storage disease(GSD) who presented with hypertrophic cardiomyopathy and to analyze the effect of five mutations identified on the acid-α-glucosidase (GAA) activity and stability.@*Method@#Three cases of children with muscle weakness were included in this study.GAA activity was analyzed in Dried Blood Spot of the patients.DNA was extracted from peripheral blood in all the patients and their parents and subjected to polymerase chain reaction and directly sequencing of GAA gene.Five mutant pcDNA3.1-myc-his-GAA expression plasmids(p.G478R, p.P361L, p.P266S, p.Q323X, p.R672Q) were constructed and transient instantaneously transfected into 293T cells to analyze the enzyme activity and stability of GAA.@*Result@#All the three children had the onset of disease at 3 years or 1.5 years of age.They presented with developmental delay, muscle weakness and hypertrophic cardiomyopathy.GAA activity of 3 patients was 2.65, 3.55 and 1.51 pmol(punch·h)(8.00-98.02)respectively. Genetic analysis found 5 mutations (p.G478R, p. P361L, p. P266S, p. Q323X, p. R672Q), and all of these 3 cases had clinical manifestations and were diagnosed as late-onset type Ⅱ glycogen storage disease.Five mutant pcDNA3.1-myc-his-GAA expression plasmids were transfected into 293T cells.Five mutant enzyme activities were found to be only 9.9%-22.5% of the wild-type enzyme activity and the protein expression of the five mutants was 32.0%-63.9% compared with the wild type.@*Conclusion@#This study reports 3 children with late-onset GSD Ⅱ accompanied by hypertrophic cardiomyopathy and compensatory stage of cardiac function in addition to limb muscle weakness.Five pathogenic mutations were identified, and these 5 mutations result in decreased GAA activity and GAA expression by in vitro functional analysis.

A case report of enzyme replacement therapy for glycogen storage disease typeⅡ / 临床儿科杂志

Objective To study the clinical characteristics and the effect of enzyme replacement therapy for late-onset glycogen storage disease typeⅡ(GSDⅡ). Methods The clinical, laboratory data and the result of genetic testing were retrospectively analyzed in a GSDⅡchild, the effect of enzyme replacement therapy was followed up and the relevant literature was reviewed. Results The patient had motor regression after 1 year old, the serum creatine kinase level is from 675 to 1286 U/L. The EMG test showed myopathic change, acid alpha-glucosidase activity is 12.0 nmol/(g·min), next generation sequencing of genetic muscle diseases panel found the GAA compound heterozygous mutations, both were tiny variations, and muscle biopsies showed the typical pathological features of GSD. The patient was given human recombinant of alpha glucoside enzyme 20 mg per kilogram of body weight, once every other week for 1 year. The weakness of the patient’s muscle strength had no obvious aggravation. Conclusions Early and adequate enzyme replacement therapy is the only possible treatment for GSDⅡ.

Clinical analysis of five cases of glycogen storage disease typeⅡin PICU / 中国小儿急救医学

Objective To investigate the clinical manifestations ofi nfantile and late-onset glycogen sot rage diseaes type Ⅱ.Mte hods We analyzed the cliin calm anifestations and prognosiso f infantile and late-onset glcy ogen storage disease type Ⅱ with a retrospective analysis of five cases admitted in PICU of Shengjing Hospital of China Medical University from 2013 to 2014.Resulst Firsts ymptoms of three infan-tile cases were dyspnea,cardiac hypertrophy,hepatomegaly,skeletal muscle weakness and low concentration of α-glucosidase A.Two cases completed gene detection.One case had frameshift mutation and missense mu-tation,and the other had two missense mutatoi n.Three infantile csa es all showed arrhythmia performance. Two cases died of fat l arrhythmia.One caes received ne zyme replacement therapy and survived.The main symptoms of two al te-onset cases who had not get gene detection were dyspnea,low muscle strength,muscle hypotonia and low concentration of ca idα-gluco sidase.One case receivedm echanicla ventilation,complicated with multiple infections,severe pneumonia andv entilator dependence,finally gave up the treatment.The other died of cardiac arrhythmia.Concluis on Infantile cases have the major symptoms of myocardial hypert o-phy,hepatomegaly,low muscular tension with rapid progression,high mortality and fatal arrhythmia.Late-on-set cases have the clinical features of respiratory failure,proximal limb muscle weakness and be susceptible to ventilator dependence and multiple infections.Enzyme replacement therapy can improve the clinical symp-toms of infantile cases.

Clinical features analysis of non-classic infantile glycogen storage disease type Ⅱ / 中华实用儿科临床杂志

Objective To summarize the clinical features of non-classic infantile glycogen storage disease type Ⅱ for early diagnosis.Methods The clinical data including the clinical manifestations and investigation of the 3 nonclassic infantile glycogen storage disease type Ⅱ were retrospectively reviewed from Jun.to Jul.2011.All the 3 cases were diagnosed by measuring acid α-glucosidase (GAA) activity in blood sample.Results All the 3 patients presented development delay,limb muscle weakness without hepatomegaly.Two cases of them presented weakness of respiratory muscle.The serum creatine kinase,aspartate aminotransferase and alanine aminotransferase were high in all the 3 patients.Electromyography studies indicated that one of the patients with susceptible myopathy,one patient with neurogenic damage and one patient with mixed damage of the neuromascular.Echographic evidence of hypertrophic cardiomyopathy was detected in 2 patients.GAA activity of the 3 patients in blood sample had diagnostic value.Conclusions Nonclassic infantile glycogen storage disease type Ⅱ is easy to be missed due to its non-significant clinical manifestations.The results suggested that GAA activity in blood sample should be screened for the patients with motor development delay,decreased muscle weakness/exercise tolerance and increased of serum creatine kinase.

Clinical, pathological and molecular genetic studies on a pedigree with late-onset Pompe's disease complicated with cerebral vascular diseases / 中华神经科杂志

Objective To report a pedigree with late-onset Pompe' s disease complicated with cerebral vascular diseases as to summarize their clinical,pathological and molecular genetic characteristics.Methods We investigated the clinical and pathological data of the two affected siblings with late-onset Pompe' s disease complicated with cerebral vascular diseases.All the 5 members of this pedigree accepted the GAA gene analysis.ResultsBoth affected siblings had progressive pelvic girdle muscle weakness from young adult age,and recently developed vertigo and ataxia.Brain imaging of them revealed multiple cerebral hemorrhage,infarction and diffuse ischemic white matter lesions.The brother had multiple aneurysms and stenoses of cerebral arteries revealed by brain CTA.However,his sister was only found to have multi-beaded stenoses of cerebral arteries.The muscle pathology of the brother showed typical vacuolar degeneration and glycogen storage in muscle fibers. The GAA enzyme activity of 2 siblings were dramatically lower than normal.A heterozygous 19 bp-deletion (c.1388-c.1406,exon 9) were found in GAA gene in the 2 siblings and their healthy mother. Conclusions Cerebrovascular involvement should be a special phenotype of Pompe' s disease.A novel heterozygous mutation c.1388del19 in GAA gene was found in this pedigree,but the relationship between the mutation and the rare clinical phenotype needs further study.

A novel nonsense mutation p.W738X of GAA gene identified in a Chinese patient with infantile glycogen storage disease type Ⅱ / 临床儿科杂志

Objective To investigate the acid α glucosidase(GAA)gene mutations and clinical features of a Chinese patient exhibiting signs and symptoms of infantile glycogen storage disease type Ⅱ(GSD Ⅱ). Methods Clinical features of the patient were reviewed,and GAA activity in the patient＇s and her parents＇ whole leukocytes were measured. GAA coding regions were amplified by polymerase chain reaction(PCR),and analyzed by direct DNA sequencing. Results The patient showed feeding difficulties,generalized hypotonia and weakness starting at 2 months of age. Cardiomegaly and cardiomyopathy were found at 4 months. She died of cardiorespiratory failure at the age of 6 months. GAA activity in leukocytes was low in the patient(17.3% of the median normal range). Genotyping revealed the patient was a heterozygote for a novel nonsense mutation p.W738X and a previously reported nonsense mutation p.E888X. The reported pseudodeficiency allele c.1726G ＞ A;2065G ＞ Awas found in the patient and her mother. Conclusions Correct diagnosis was made for this patient by combination of GAA activity assay and genetic analysis. From the clinical course,this patient should be classified as infantile type of GSD Ⅱ,suggesting that the novel mutation p.W738X may have a damaging effect on the function of GAA. Pseudodeficiency allele found in this family highlights the importance of genetic analysis of GAA when performing diagnosis and prenatal diagnosis for the affected families,as this allele causes low GAA activity in normal individuals.

Clinical and pathological features of 20 patients of glycogen storage disease type Ⅱ / 中华神经科杂志

Objective To summarize the clinical and pathological features of glycogen storage disease (GSD) type Ⅱ. Methods The clinical and pathological data of the 20 GSD type Ⅱ patients were reviewed. Results One patient with infantile-onset mainly presented hypotonia, muscle weakness, feeding difficulties, pulmonary infection and cardiomyopathy insufficiency and increase of serum creatine kinase (778 IU/L) and echographic evidence of hypertrophic cardiomyopathy were detected. Electromyography studies indicated a definite myopathy. Nineteen cases were late-onset, presenting a slowly progressive proximal myopathy with truncal involvement or with symptoms dominated by respiratory insufficiency. Not all muscles were equally affected. Increase of serum creatine kinase (208-2600 IU/L) was detected in 14 patients and normal level in 1 patient. Electromyography studies indicated a definite myopathy in 9 patients,with abnormal irritability in 1 patient and susceptible in 4 patients and myotonic discharge in 1 patient and no abnormalities in 2 patients. Echographic evidence of thickening of the interventricular septum and pulmonary hypertension were detected in 2 patients respectively. The common light microscopic feature of all case was a vacuolar myopathy with high glycogen content and acid phosphatase activity in the vacuoles. Conclusions GSD type Ⅱ often presents slowly progressive myopathy which often affect the toro and respiratory muscles.In most patients the serum creatine kinase level is elevated slightly. Muscle biopsy is of use to make the definite diagnosis of this disease.

Clinical and pathological features of Danon disease associated with a novel lysosome-associated membrane protein-2B mutation / 中华神经科杂志

Objectives To report the clinical and myopathological features in a case with Danon disease caused by a novel mutation in the lysosome-associated membrane protein-2 ( LAMP2 ) B gene.Methods A 16-year-old boy presenting progressive muscle weakness and atrophy, accompanied with spinal ankylosis was clinically evaluated including electrocardiogram, echocardiogram and electromyogram.Muscle biopsy was carried out in the patient.The histological staining, ultrastructural examination, and immunohistochemical staining with antibodies against dystrophin, merosin and C5b9 were performed in frozen sections.LAMP2B sequence was analyzed in the patient and his parents.Results Electrocardiogram in the patient showed Ⅰ atrioventricular block; echocardiogram revealed focal hypertrophy in mitral valve with mild cardiac diastolic dysfunction; electromyogram indicated myogenic and neurogenic patterns.Muscle pathology study revealed numerous vacuoles located at the fibers.Dystrophin, merosin and C5b9 was immuno-positive around the vacuoles.Electron microscopy revealed vacuoles surrounded by sarcolemma and abnormal lysosome aggregating at the fibers.A novel nonsense mutation ( K402X ) in the LAMP2B gene has been identified in the patient but not in his mother and 50 normal controls.Conclusions Danon disease caused by K402X mutation in C-terminus of LAMP2B presented benign course of the disease characterized by prominent vacuolar skeletal myopathy, mild cardiac abnormalities and peripheral neuropathy.