CASE REPORT Long-term follow-up results in enzyme replacement therapy for Pompe disease: a case report Monica Del Rizzo & Marina Fanin & Alessia Cerutti & Chiara Cazzorla & Ornella Milanesi & Anna Chiara Nascimbeni & Corrado Angelini & Laura Giordano & Andrea Bordugo & Alberto B. Burlina Received: 14 June 2010 / Revised: 11 August 2010 / Accepted: 23 August 2010 # SSIEM and Springer 2010 Abstract Pompe disease (PD) is a metabolic myopathy caused by a deficiency of acid-alpha glucosidase (GAA), a lysosomal enzyme that cleaves glycogen. The classic infantile-onset form is characterised by severe hypotonia and cardiomyopathy. Untreated patients usually die within the first year of life due to cardiorespiratory failure. Several studies involving patients with infantile-onset PD have shown that enzyme replacement therapy (ERT) with alglucosidase alfa, recombinant human GAA (rhGAA), significantly prolongs survival, decreases cardiomegaly, and improves cardiac function and conduction abnormali- ties. However, the efficacy on motor, cognitive and social milestones appears to be more related to the condition of the patient before the start of treatment. To date, the sample of early diagnosed and treated patients is small and the length of follow-up is still limited. We report the results of a long-term follow-up of one patient presenting severe bradycardia and cardiomyopathy at birth, diag- nosed in the third day of life and successfully treated by ERT. Serum muscle enzymes at diagnosis were AST 200 U/L, ALT 99 U/L and CPK 731 U/L (n.v. 0-295); the molecular study identified the homozygous missense mutation c.1933 G> A p.Asp645Asn (GAA exon 14). Left Ventricular Mass Index (LVMI) at baseline was 171 g/m 2 (Z-score = 4.3) and decreased to normal values since the 3-month follow-up. A muscle biopsy performed at 18 months after the start of therapy, showed only a low degree of muscle involvement. To our knowledge, this is the longest ERT treatment follow-up in a symptomatic neonatal patient with Pompe disease. Abbreviations CRIM Cross-reactive immunological material DBS Dried blood spot ERT Enzyme replacement therapy ECG Electrocardiogram EMG Electromyography GAA Acid-alpha glucosidase LVMI Left ventricular mass index MS/MS Tandem mass spectrometry PAS Periodic acid-Schiff PCR Polymerase chain reaction PD Pompe disease rhGAA Alglucosidase alfa Introduction Infantile-onset glycogen storage disease type II (OMIM # 232300), also known as Pompe disease, is a rare autosomic recessive form due to a complete or near-complete Communicated by: Olaf Bodamer Competing interests: None declared. M. Del Rizzo : C. Cazzorla : L. Giordano : A. Bordugo : A. B. Burlina (*) Division of Metabolic Diseases, Department of Paediatrics, University Hospital Padua, Via Giustiniani 3, 35128 Padua, Italy e-mail: burlina@pediatria.unipd.it A. Cerutti : O. Milanesi Division of Pediatric Cardiology, Department of Pediatrics, University Hospital Padua, Padua, Italy M. Fanin : A. C. Nascimbeni : C. Angelini Department of Neurosciences, University Hospital Padua, Padua, Italy J Inherit Metab Dis DOI 10.1007/s10545-010-9195-2