scholarly journals Newborn Screening for Pompe Disease

2020 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
Takaaki Sawada ◽  
Jun Kido ◽  
Kimitoshi Nakamura

Glycogen storage disease type II (also known as Pompe disease (PD)) is an autosomal recessive disorder caused by defects in α-glucosidase (AαGlu), resulting in lysosomal glycogen accumulation in skeletal and heart muscles. Accumulation and tissue damage rates depend on residual enzyme activity. Enzyme replacement therapy (ERT) should be started before symptoms are apparent in order to achieve optimal outcomes. Early initiation of ERT in infantile-onset PD improves survival, reduces the need for ventilation, results in earlier independent walking, and enhances patient quality of life. Newborn screening (NBS) is the optimal approach for early diagnosis and treatment of PD. In NBS for PD, measurement of AαGlu enzyme activity in dried blood spots (DBSs) is conducted using fluorometry, tandem mass spectrometry, or digital microfluidic fluorometry. The presence of pseudodeficiency alleles, which are frequent in Asian populations, interferes with NBS for PD, and current NBS systems cannot discriminate between pseudodeficiency and cases with PD or potential PD. The combination of GAA gene analysis with NBS is essential for definitive diagnoses of PD. In this review, we introduce our experiences and discuss NBS programs for PD implemented in various countries.

Author(s):  
Ans T. van der Ploeg ◽  
Pascal Laforêt

Pompe disease, also named acid maltase deficiency and glycogen storage disease type II (GSDII), is a rare autosomal recessive disorder caused by the deficiency of the glycogen-degrading lysosomal enzyme acid α‎-glucosidase. The clinical spectrum of this disease is broad, varying from a lethal infantile-onset generalized myopathy including cardiomyopathy, to late-onset slowly progressive muscle weakness mimicking limb-girdle muscular dystrophy. Respiratory insufficiency is a frequent complication and the main cause of death. The prognosis of Pompe disease has changed considerably with the use of enzyme replacement therapy using recombinant acid α‎-glucosidase (alglucosidase alfa), which has been widely available since 2006. Improvements in survival and major motor achievements can be observed in patients with infantile forms, and recent studies demonstrate improvement of walking distance and stabilization of pulmonary function in late-onset forms. A longer-term study of the safety and efficacy of ERT, based on data gathering across the complete spectrum of Pompe disease via national or international patient registries, is needed in order to formulate more precise guidelines for treatment.


Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1339
Author(s):  
Naresh K. Meena ◽  
Nina Raben

Pompe disease, also known as glycogen storage disease type II, is caused by the lack or deficiency of a single enzyme, lysosomal acid alpha-glucosidase, leading to severe cardiac and skeletal muscle myopathy due to progressive accumulation of glycogen. The discovery that acid alpha-glucosidase resides in the lysosome gave rise to the concept of lysosomal storage diseases, and Pompe disease became the first among many monogenic diseases caused by loss of lysosomal enzyme activities. The only disease-specific treatment available for Pompe disease patients is enzyme replacement therapy (ERT) which aims to halt the natural course of the illness. Both the success and limitations of ERT provided novel insights in the pathophysiology of the disease and motivated the scientific community to develop the next generation of therapies that have already progressed to the clinic.


2001 ◽  
Vol 47 (8) ◽  
pp. 1378-1383 ◽  
Author(s):  
Kandiah Umapathysivam ◽  
John J Hopwood ◽  
Peter J Meikle

Abstract Background: Pompe disease is an autosomal recessive disorder of glycogen metabolism that is characterized by a deficiency of the lysosomal acid α-glucosidase. Enzyme replacement therapy for the infantile and juvenile forms of Pompe disease currently is undergoing clinical trials. Early diagnosis before the onset of irreversible pathology is thought to be critical for maximum efficacy of current and proposed therapies. In the absence of a family history, the presymptomatic detection of these disorders ideally can be achieved through a newborn-screening program. Currently, the clinical diagnosis of Pompe disease is confirmed by the virtual absence, in infantile onset, or a marked reduction, in juvenile and adult onset, of acid α-glucosidase activity in muscle biopsies and cultured fibroblasts. These assays are invasive and not suited to large-scale screening. Methods: A sensitive immune-capture enzyme activity assay for the measurement of acid α-glucosidase protein was developed and used to determine the activity of this enzyme in dried-blood spots from newborn and adult controls, Pompe-affected individuals, and obligate heterozygotes. Results: Pompe-affected individuals showed an almost total absence of acid α-glucosidase activity in blood spots. The assay showed a sensitivity and specificity of 100% for the identification of Pompe-affected individuals. Conclusions: The determination of acid α-glucosidase activity in dried-blood spots is a useful, noninvasive diagnostic assay for the identification of Pompe disease. With further validation, this procedure could be adapted for use with blood spots collected in newborn-screening programs.


2020 ◽  
Vol 6 (3) ◽  
pp. 55
Author(s):  
Joan M. Keutzer

When clinical trials for enzyme replacement therapy for Pompe disease commenced, a need for newborn screening (NBS) for Pompe disease was recognized. Two methods for NBS for Pompe disease by measuring acid α-glucosidase in dried blood spots on filter paper were developed in an international collaborative research effort led by Genzyme. Both methods were used successfully in NBS pilot programs to demonstrate the feasibility of NBS for Pompe disease. Since 2009, all babies born in Taiwan have been screened for Pompe disease. Pompe disease was added to the Recommended Uniform (Newborn) Screening Panel in the United States in 2015. NBS for Pompe disease is possible because of the unprecedented and selfless collaborations of countless international experts who shared their thoughts and data freely with the common goal of establishing NBS for Pompe disease expeditiously.


2021 ◽  
pp. 112972982199948
Author(s):  
Matthew Ostroff ◽  
Punita Gupta ◽  
Daniel Garcia

Pompe disease is an autosomal recessive glycogen storage disorder resulting in progressive glycogen accumulation expressed in infancy with cardiomyopathy and skeletal myopathy. Without treatment by enzyme replacement therapy (ERT), life expectancy is less than 2 years. The cross-reactive immunologic material (CRIM) positive or negative status is the basis for the response to ERT. CRIM-negative patients mount an immune response to ERT, making this the most dangerous presentation. The following case study describes the 5-year course of the first successful treatment of an in utero CRIM-negative Pompe disease patient with prophylactic immune tolerance induction (ITI) and administration of ERT given within the first 2 days of life followed by ultrasound guided vascular access that facilitated by bi-weekly infusions and extensive phlebotomy.


2020 ◽  
Vol 6 (4) ◽  
pp. 96
Author(s):  
Zoltan Lukacs ◽  
Petra Oliva ◽  
Paulina Nieves Cobos ◽  
Jacob Scott ◽  
Thomas P. Mechtler ◽  
...  

Pompe disease (GSD II) is an autosomal recessive disorder caused by deficiency of the lysosomal enzyme acid-α-glucosidase (GAA, EC 3.2.1.20), leading to generalized accumulation of lysosomal glycogen especially in the heart, skeletal, and smooth muscle, and the nervous system. It is generally classified based on the age of onset as infantile (IOPD) presenting during the first year of life, and late onset (LOPD) when it presents afterwards. In our study, a cohort of 13,627 samples were tested between January 2017 and December 2018 for acid-α-glucosidase (GAA, EC 3.2.1.20) deficiency either by fluorometry or tandem mass spectrometry (MS). Testing was performed for patients who displayed conditions of unknown etiology, e.g., CK elevations or cardiomyopathy, in the case of infantile patients. On average 8% of samples showed activity below the reference range and were further assessed by another enzyme activity measurement or molecular genetic analysis. Pre-analytical conditions, like proper drying, greatly affect enzyme activity, and should be assessed with measurement of reference enzyme(s). In conclusion, at-risk testing can provide a good first step for the future introduction of newborn screening for Pompe disease. It yields immediate benefits for the patients regarding the availability and timeliness of the diagnosis. In addition, the laboratory can introduce the required methodology and gain insights in the evaluation of results in a lower throughput environment. Finally, awareness of such a rare condition is increased tremendously among local physicians which can aid in the introduction newborn screening.


2017 ◽  
Vol 9 (418) ◽  
pp. eaam6375 ◽  
Author(s):  
Francesco Puzzo ◽  
Pasqualina Colella ◽  
Maria G. Biferi ◽  
Deeksha Bali ◽  
Nicole K. Paulk ◽  
...  

Glycogen storage disease type II or Pompe disease is a severe neuromuscular disorder caused by mutations in the lysosomal enzyme, acid α-glucosidase (GAA), which result in pathological accumulation of glycogen throughout the body. Enzyme replacement therapy is available for Pompe disease; however, it has limited efficacy, has high immunogenicity, and fails to correct pathological glycogen accumulation in nervous tissue and skeletal muscle. Using bioinformatics analysis and protein engineering, we developed transgenes encoding GAA that could be expressed and secreted by hepatocytes. Then, we used adeno-associated virus (AAV) vectors optimized for hepatic expression to deliver the GAA transgenes to Gaa knockout (Gaa−/−) mice, a model of Pompe disease. Therapeutic gene transfer to the liver rescued glycogen accumulation in muscle and the central nervous system, and ameliorated cardiac hypertrophy as well as muscle and respiratory dysfunction in the Gaa−/− mice; mouse survival was also increased. Secretable GAA showed improved therapeutic efficacy and lower immunogenicity compared to nonengineered GAA. Scale-up to nonhuman primates, and modeling of GAA expression in primary human hepatocytes using hepatotropic AAV vectors, demonstrated the therapeutic potential of AAV vector–mediated liver expression of secretable GAA for treating pathological glycogen accumulation in multiple tissues in Pompe disease.


2021 ◽  
Vol 22 (7) ◽  
pp. 3625
Author(s):  
Filomena Napolitano ◽  
Giorgia Bruno ◽  
Chiara Terracciano ◽  
Giuseppina Franzese ◽  
Nicole Piera Palomba ◽  
...  

Pompe disease is an autosomal recessive disorder caused by a deficiency in the enzyme acid alpha-glucosidase. The late-onset form of Pompe disease (LOPD) is characterized by a slowly progressing proximal muscle weakness, often involving respiratory muscles. In LOPD, the levels of GAA enzyme activity and the severity of the clinical pictures may be highly variable among individuals, even in those who harbour the same combination of GAA mutations. The result is an unpredictable genotype–phenotype correlation. The purpose of this study was to identify the genetic factors responsible for the progression, severity and drug response in LOPD. We report here on a detailed clinical, morphological and genetic study, including a whole exome sequencing (WES) analysis of 11 adult LOPD siblings belonging to two Italian families carrying compound heterozygous GAA mutations. We disclosed a heterogeneous pattern of myopathic impairment, associated, among others, with cardiac defects, intracranial vessels abnormality, osteoporosis, vitamin D deficiency, obesity and adverse response to enzyme replacement therapy (ERT). We identified deleterious variants in the genes involved in autophagy, immunity and bone metabolism, which contributed to the severity of the clinical symptoms observed in the LOPD patients. This study emphasizes the multisystem nature of LOPD and highlights the polygenic nature of the complex phenotype disclosed in these patients.


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