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.

Pseudodeficiency alleles affect the newborn screening of glycogen storage disease typeⅡ / 中华检验医学杂志

Objective To investigate the effect of pseudodeficiency alleles on the newborn screening of glycogen storage disease typeⅡ(GSDⅡ) by using afluorometric enzymatic assay to determine acidα-glucosidase (GAA) activity in dried blood spot (DBS). Methods A total of 30507 newborns' DBSs, obtained from Newborn Screening Center of Xinhua Hospital Shanghai Jiao Tong University School of Medicine from May to December 2017, were screened for GSDⅡby fluorometric enzymatic assay of GAA activity. The suspected positive DBSs after the first and second screening were directly analyzed by Sanger sequencing of GAA to confirm the diagnosis. Retrospective analysis of 3172 controls without GSDⅡand 36 GSDⅡpatients were conducted to investigate the carrier status of pseudodeficiency alleles. Statistical analysis of frequency of pseudodeficiency alleles were carried out by Chi-square test or Fisher exact probability test. Results GAA activity of 30507 newborns showed a positively skewed distribution. Twenty-nine cases of newborns, suspected to be GSDⅡwere confirmed to be normal with genetic analysis of the original DBSs. Among the 29 suspected positive cases, 24 cases were homozygous for pseudodeficiency alleles c. [1726A/A; 2065A/A], and the other 5 cases were c. [1726G/A; 2065G/A] heterozygote. The frequency of c. 1726G>Ahomozygote in 3172 non-GSDⅡcontrols was 2.08％(66/3172), and c. 1726G>A homozygote occurred in allelic conjunction with c. 2065G>Ahomozygote. Frequency of c. [1726A; 2065A] haplotype in 3172 controls was 3.2％(206/6344). Frequency of c. [1726A/A;2065A/A] homozygote in 36 GSDⅡpatients (16.67％, 6/36) was significantly higher than that in non-GSDⅡcontrols(2.08％, 66/3172) (χ2=34.517, P<0.001). Conclusions Pseudodeficiency alleles show a high frequency in Chinese, which leads to a high false positive rate in the newborns screening of GSDⅡ.The afterword genetic analysis of the original DBS after the GAA activity screening could reduce the effect of pseudodeficiency alleles on the newborns screening of GSDⅡ.

Pseudodeficiency alleles affect the newborn screening of glycogen storage disease typeⅡ / 中华检验医学杂志

Objective@#To investigate the effect of pseudodeficiency alleles on the newborn screening of glycogen storage disease type Ⅱ(GSDⅡ) by using afluorometric enzymatic assay to determine acid α-glucosidase (GAA) activity in dried blood spot (DBS).@*Methods@#A total of 30 507 newborns′ DBSs, obtained from Newborn Screening Center of Xinhua Hospital Shanghai Jiao Tong University School of Medicine from May to December 2017, were screened for GSD Ⅱ by fluorometric enzymatic assay of GAA activity. The suspected positive DBSs after the first and second screening were directly analyzed by Sanger sequencing of GAA to confirm the diagnosis. Retrospective analysis of 3 172 controls without GSDⅡand 36 GSD Ⅱ patients were conducted to investigate the carrier status of pseudodeficiency alleles. Statistical analysis of frequency of pseudodeficiency alleles were carried out by Chi-square test or Fisher exact probability test.@*Results@#GAA activity of 30 507 newborns showed a positively skewed distribution.Twenty-nine cases of newborns, suspected to be GSDⅡwere confirmed to be normal with genetic analysis of the original DBSs. Among the 29 suspected positive cases, 24 cases were homozygous for pseudodeficiency alleles c.[1726A/A; 2065A/A], and the other 5 cases were c.[1726G/A; 2065G/A] heterozygote. The frequency of c.1726G>Ahomozygote in 3 172 non-GSD Ⅱcontrols was 2.08% (66/3 172), and c.1726G>A homozygote occurred in allelic conjunction with c.2065G>Ahomozygote. Frequency of c.[1726A; 2065A] haplotype in 3 172 controls was 3.2%(206/6 344). Frequency of c.[1726A/A; 2065A/A] homozygote in 36 GSDⅡpatients (16.67%, 6/36) was significantly higher than that in non-GSD Ⅱcontrols(2.08%, 66/3 172) (χ2=34.517, P<0.001).@*Conclusions@#Pseudodeficiency alleles show a high frequency in Chinese, which leads to a high false positive rate in the newborns screening of GSDⅡ.The afterword genetic analysis of the original DBS after the GAA activity screening could reduce the effect of pseudodeficiency alleles on the newborns screening of GSDⅡ.

Diagnóstico y tratamiento de la enfermedad de Pompe / Diagnosis and treatment of Pompe disease

INTRODUCCIÓN: la enfermedad de Pompe es una glucogenosis tipo II con patrón de herencia autosómico recesivo, causada por la deficiencia de la enzima alfa-glucosidasa ácida, que provoca acúmulo de glucógeno en los lisosomas de los macrófagos. El gen está mapeado en el cromosoma 17q25, y han sido detectadas más de 460 mutaciones. Están descritas 3 formas clínicas de la enfermedad, que incluyen, la variedad infantil, la juvenil y la tardía. La variedad infantil se caracteriza por miocardiopatía hipertrófica o infiltrativa, hipotonía, hepatomegalia y macroglosia. En la variedad juvenil hay fiebre recurrente, infecciones respiratorias a repetición y discapacidad motora progresiva. La terapia de reemplazo enzimático modifica el curso clínico de la enfermedad. PRESENTACIÓN DE CASOS: se presentan los elementos al diagnóstico de 4 casos con esta enfermedad, 3 de ellos con la variedad infantil y uno con la variedad juvenil, y se discuten los resultados de estudio molecular. Se informa la evolución clínica de 2 de ellos, luego de 6 meses y un año de tratamiento con la terapia de reemplazo enzimático con alfa-glucosidasa ácida (myozyme), lo que ha llevado a la mejoría de parámetros bioquímicos y clínicos en ambos casos. CONCLUSIONES: en pacientes con enfermedad de Pompe la cuidadosa evaluación clínica para diagnosticar precozmente la enfermedad y el comienzo de la terapia de reemplazo enzimático contribuyen a mejorar las funciones musculares, motoras y cardiovasculares, lo cual impacta en la supervivencia y calidad de vida de estos niños(AU)

INTRODUCTION: Pompe disease is a type II glycogenosis with recessive autosomal inheritance pattern, which is caused by the acid alpha-glucosidase enzyme that brings about buildup of glycogen in macrophage lysosomes. The gene is already mapped in Chromosome 17q25 and has been so far detected over 460 mutations. Three clinical forms of disease were described, including infantile, juvenile and late-onset varieties. The infantile variety is characterized by hpertrophic or infiltratin myocardiopathy, hypotonia, hepatomegaly and macroglossia. The juvenile type comprises recurrent fever, repeated respiratory infections and progressive motor disability. Enzyme replacement therapy changes the clinical course of disease. CASE PRESENTATION: the elements for diagnosis of 4 cases were submitted, 3 of them with infantile form and one with juvenile one. The results of the molecular study were discussed. The clinical progress of 2 of them after 6 monts and one year of treatment with the enzymatic replacement therapy using acid alpha-glucosidase (myozyme), which led to improvement of biochemical and clinical parameters in both cases. CONCLUSIONS: careful clinical assessment of patients with Pompe disease to early diagnose it and the onset of the enzyme replacement therapy help to improve muscle, motor and cardiovascular functions, which has an impact on survival and quality of life of these children(AU)

Guidelines for the diagnosis, treatment and clinical monitoring of patients with juvenile and adult Pompe disease / Diretriz para o diagnóstico, tratamento e acompanhamento clínico de pacientes com doença de Pompe juvenil e do adulto

ABSTRACT Pompe disease (PD) is a potentially lethal illness involving irreversible muscle damage resulting from glycogen storage in muscle fiber and activation of autophagic pathways. A promising therapeutic perspective for PD is enzyme replacement therapy (ERT) with the human recombinant enzyme acid alpha-glucosidase (Myozyme®). The need to organize a diagnostic flowchart, systematize clinical follow-up, and establish new therapeutic recommendations has become vital, as ERT ensures greater patient longevity. A task force of experienced clinicians outlined a protocol for diagnosis, monitoring, treatment, genetic counseling, and rehabilitation for PD patients. The study was conducted under the coordination of REBREPOM, the Brazilian Network for Studies of PD. The meeting of these experts took place in October 2013, at L’Hotel Port Bay in São Paulo, Brazil. In August 2014, the text was reassessed and updated. Given the rarity of PD and limited high-impact publications, experts submitted their views.

RESUMO A doença de Pompe (DP) é uma doença grave, potencialmente letal, devida ao depósito de glicogênio na fibra muscular e ativação de vias autofágicas. Tratamento promissor para a DP é a reposição enzimática com a enzima recombinante humana alfa-glicosidase ácida (rhAGA -Myozyme®). A necessidade de organizar uma propedêutica diagnóstica, sistematizar o seguimento clínico e sedimentar as novas recomendações terapêuticas tornaram-se vitais à medida que o tratamento permite uma maior longevidade aos pacientes. Uma força-tarefa de clínicos experientes no manejo da DP foi constituída para elaborar um protocolo para o diagnóstico, acompanhamento clínico, tratamento, aconselhamento genético, entre outras considerações voltadas ao paciente adulto. O estudo foi realizado sob a coordenação da Rede Brasileira de Estudos da Doença de Pompe (REBREPOM). Diante da raridade da DP e escassez de trabalhos de alto impacto de evidência científica, os especialistas emitiram suas opiniões.

Analysis on novel mutations in GAA gene of a Chinese family with two siblings affected with juvenile onset form glycogen storage disease Ⅱ / 重庆医学

Objective To identify a novel pathogenicity mutation of acid alpha‐glucosidase(GAA) gene in a Chinese family with two siblings affected with juvenile onset form glycogen storage disease Ⅱ(GSD Ⅱ) .Methods The clinical and family data of two siblings presenting recurrent respiratory tract infections ,respiratory failure associated with systemic muscle weakness ,were an‐alyzed and diagnosed with GSD Ⅱ by detecting alpha‐1 ,4‐glucosidase activity .DNA was extracted from peripheral blood of the proband ,younger brother and his parents .All 20 exons and the intron‐exon splice sites of GAA gene were amplified by polymerase chain reaction (PCR) .Mutations were detected by direct sequencing the PCR products .Results The younger brother was found to be compound heterozygous for two mutations in the GAA gene :c .1216G>A (p .Asp406Asn) missense mutation in the exon 8 from his father and c .1935C>A (p .Asp645Glu) missense mutation in the exon 14 from his mother .Conclusion The compound hetero‐zygous c .1216G>A and c .1935C>A mutations caused the juvenile onset form GSD Ⅱ characterized by dyspnea and cardiac hyper‐trophy .The novel c .1216G>A mutation may be related to the juvenile onset form GSD Ⅱ .

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.

Two Patients with Atypical Infantile Pompe Disease Presenting with Hypertrophic Cardiomyopathy

Pompe disease (glycogen storage disease type II) is an autosomal recessive disorder caused by deficiency of acid-alpha-glucosidase (GAA) resulting in lysosomal glycogen accumulation in multiple tissue, particularly cardiac and skeletal muscle. The classic infantile form of Pompe disease is characterized by marked cardiomegaly, respiratory failure and severe generalized hypotonia. Most patients die from cardiorespiratory failure or respiratory infection within the first year or two of life without treatment. A "non-classic" phenotype presents with less severe clinical feature and slow progression of disease. We report two patients with non-classic infantile Pompe disease from one family manifested hypertrophic cardiomyopathy and progressive proximal weakness.

Relato do primeiro paciente brasileiro com a forma infantil da doença de Pompe tratado com alfa-glicosidase recombinante humana / Report of the first Brazilian infantile Pompe disease patient to be treated with recombinant human acid alpha-glucosidase

Objetivo: Relatar o primeiro caso de forma infantil da doença de Pompe tratado no Brasil. Descrição: Trata-se de doença de depósito lisossomal que se caracteriza por defeitos da enzima alfa-glicosidase ácida, com acúmulo intracelular de glicogênio, principalmente nos músculos. São descritas a forma infantil e tardia. Desde 2006, está disponível tratamento com enzima recombinante humana. Descreve-se o primeiro caso de forma infantil da doença tratado no Brasil. Trata-se de menina com 2,5 meses de idade e progressão rápida da doença, com perda dos movimentos dos membros, miocardiopatia hipertrófica e insuficiência respiratória aos 7 meses de idade. Após 10 meses de tratamento, apresentou boa resposta clínica, com remissão da insuficiência respiratória, recuperação parcial dos movimentos dos membros e melhora importante do quadro cardiológico. Comentários: Apesar de pouco freqüente, a forma infantil da doença de Pompe é letal. A disponibilidade de tratamento eficaz aumenta a necessidade de conhecimento e diagnóstico precoce da doença.

Objective: To describe the first case of infantile Pompe disease to be treated in Brazil. Description: Pompe disease is a glycogen storage disease related to defects in the acid alpha-glucosidase enzyme, leading to an intracellular accumulation of glycogen, mainly in muscles. Two forms are described: infantile and juvenile. Since 2006, treatment with recombinant human acid alpha-glucosidase has been available. This article describes the first case of infantile Pompe disease treated in Brazil. A girl presented at 2.5 months of age with rapid disease progression, exhibiting severe hypotonia, loss of movements in both upper and lower limbs and hypertrophic cardiomyopathy, progressing to respiratory failure by the age of 7 months. After 10 months of treatment, she exhibited a good clinical response, with remission of the respiratory failure, partial recovery of arm and leg movements and improvement of cardiologic condition. Comments: Despite its low incidence, infantile Pompe disease is lethal. The availability of an effective treatment has created an urgent need to improve knowledge and early diagnosis of this disease.