Pompe disease

Pompe disease
Jensflorian · CC BY-SA 3.0 · source
Name	Pompe disease
Synonyms	Glycogen storage disease type II
Field	Genetics, Internal medicine
Symptoms	Muscle weakness, Respiratory failure, Cardiomyopathy
Complications	Aspiration pneumonia, Heart failure
Onset	Infantile, Childhood, Adulthood
Duration	Lifelong
Causes	Mutations in GAA gene
Diagnosis	Genetic testing, Enzyme assay
Differential	Duchenne muscular dystrophy, Becker muscular dystrophy
Treatment	Enzyme replacement therapy, Supportive care
Prognosis	Variable

Pompe disease Pompe disease is a rare inherited lysosomal storage disease characterized by deficient activity of the acid alpha-glucosidase enzyme due to pathogenic variants in the GAA gene, leading to glycogen accumulation in lysosomes of cardiac, skeletal, and smooth muscle. First described by J. C. Pompe in 1932, the disorder spans a clinical continuum from rapidly fatal infantile-onset forms to milder late-onset presentations affecting adults. Management includes disease-specific enzyme replacement therapy and multidisciplinary supportive care coordinated among specialists from Pediatrics, Neurology, and Cardiology.

Introduction

Pompe disease, also known as glycogen storage disease type II, was identified in a muscle biopsy reported by J. C. Pompe and later characterized biochemically with contributions from researchers associated with Harvard Medical School, Massachusetts General Hospital, and other centers. The condition exemplifies translational progress from enzyme characterization—pioneered in laboratories at institutions such as National Institutes of Health—to therapeutic development led by biotechnology firms and trial consortia including Genzyme. Historical milestones intersect with regulatory decisions by agencies like the Food and Drug Administration and health-technology assessments by bodies such as the National Institute for Health and Care Excellence.

Genetics and Pathophysiology

Pompe disease results from autosomal recessive inheritance of pathogenic variants in the GAA gene located on chromosome 17; allelic heterogeneity was elucidated in studies at University of Cambridge, University of Lund, and University of Tokyo. Loss of acid alpha-glucosidase activity causes intralysosomal glycogen accumulation documented in electron microscopy reports from laboratories at Johns Hopkins University and University College London. Secondary pathways implicated include impaired autophagy described by investigators at Massachusetts Institute of Technology and mitochondrial dysfunction reported by groups at University of California, San Diego. Genotype–phenotype correlations were refined through patient registries maintained by networks such as the International Pompe Association and natural history studies coordinated by European Pompe Consortium.

Clinical Presentation and Classification

Clinical manifestations form a spectrum: classical infantile-onset with hypertrophic cardiomyopathy and profound hypotonia, non-classical infantile and childhood forms with variable cardiac involvement, and late-onset forms presenting in adolescence or adulthood with progressive limb-girdle and respiratory muscle weakness. Seminal case series from Mayo Clinic, Cleveland Clinic, and Nationwide Children’s Hospital delineated cardiac phenotypes and feeding complications leading to interventions documented in reports by American Heart Association and European Society of Cardiology. Respiratory insufficiency requiring ventilatory support is described in cohort analyses from Columbia University and University of Toronto. Differential diagnosis commonly references disorders cataloged at Muscular Dystrophy Association and comparative studies from Cedars-Sinai Medical Center.

Diagnosis

Diagnostic approaches integrate assays measuring residual acid alpha-glucosidase activity in blood or fibroblasts developed at reference laboratories such as those affiliated with Mayo Clinic Laboratories and National Medical Genetics Center. Confirmatory molecular testing is performed by clinical genetics centers at Children’s Hospital of Philadelphia and commercial laboratories accredited by American College of Medical Genetics and Genomics. Newborn screening programs initiated in pilot projects in Taiwan and expanded following recommendations from Advisory Committee on Heritable Disorders in Newborns and Children use dried blood spot enzyme assays and reflex sequencing. Ancillary investigations include echocardiography as per guidelines from American College of Cardiology, respiratory function testing endorsed by American Thoracic Society, and muscle MRI protocols standardized by research groups at University of Milan.

Treatment and Management

Disease-specific therapy centers on recombinant human acid alpha-glucosidase administered via intravenous enzyme replacement therapy (ERT) developed and approved through clinical trials led by industry and academic collaborators, including pivotal studies at Mount Sinai Hospital and trial networks organized by ClinicalTrials.gov sponsors. Immunomodulation strategies for CRIM-negative patients were advanced in protocols from Boston Children’s Hospital and consensus statements by international expert panels convened at meetings of World Muscle Society. Supportive management involves multidisciplinary teams spanning Physical therapy services at institutions like Sheba Medical Center, respiratory care guided by ERS and ATS standards, and nutritional and feeding interventions implemented in pediatric centers including Great Ormond Street Hospital.

Prognosis and Epidemiology

Prognosis varies with age at onset, residual enzyme activity, and treatment access; infantile-onset untreated cohorts reported in historical series from Johns Hopkins Hospital showed high early mortality, whereas treated populations in registries from International Pompe Registry and national cohorts in Netherlands and France demonstrate improved survival and motor outcomes. Incidence estimates differ by region—higher detection in Taiwan newborn screening studies, variable prevalence reported in databases from United Kingdom and United States—with carrier frequencies mapped by population genetics research groups at Broad Institute and Wellcome Sanger Institute. Ongoing observational studies and trials at centers such as Royal Brompton Hospital and University of Pittsburgh continue to refine long-term outcomes and health-economic evaluations by agencies like Institute for Clinical and Economic Review.

Category:Genetic disorders