Case Report EnzymeReplacementTherapy(ERT)onHeartFunctionChanges theOutcomeinPatientswithInfantile-OnsetPompeDisease:A Familial History MarcoLecis , 1 KatiaRossi , 2 MariaElenaGuerzoni , 3 Ilaria Mariotti , 3 andLorenzoIughetti 1,3 1 Post-Graduate School of Pediatrics, Department of Medical and Surgical Sciences for Mother Children and Adults, University of Modena and Reggio Emilia, Via Del Pozzo 71, Modena 41124, Italy 2 Neonatology Unit, Department of Medical and Surgical Sciences for Mother Children and Adults, University of Modena and Reggio Emilia, Via Del Pozzo 71, Modena 41124, Italy 3 Pediatrics Unit, Department of Medical and Surgical Sciences for Mother Children and Adults, University of Modena and Reggio Emilia, Via Del Pozzo 71, Modena 41124, Italy CorrespondenceshouldbeaddressedtoLorenzoIughetti;iughetti.lorenzo@unimore.it Received 11 August 2022; Revised 8 November 2022; Accepted 6 February 2023; Published 17 February 2023 AcademicEditor:VjekoslavKrzelj Copyright©2023MarcoLecisetal.TisisanopenaccessarticledistributedundertheCreativeCommonsAttributionLicense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Lysosomal acid alpha-glucosidase (GAA) defciency, also known as Pompe disease, is an autosomal recessive disorder that leads to the accumulation of glycogen in lysosomes and cytoplasm, resulting in tissue destruction. Infantile-onset GAA defciency is characterized by cardiomyopathy and severe generalized hypotonia. Without treatment, most patients die withinthefrsttwoyearsoflife.TedemonstrationofreducedGAAactivity,followedbysequencingoftheGAAgene,confrms the disease. GAA defciency is currently treated with enzyme replacement therapy (ERT) with improved clinical outcomes and survival. Case Presentation. We describe the case of DGAA in two siblings, in which the diagnostic time point, treatment, and outcomes were completely diferent. Te girl was diagnosed with DGAA at the age of 6months during investigations for poor weight gain and excessive sleepiness. Te fnding of severe cardiomyopathy through EKG and echocardiography led to the suspicionofstoragedisease,andtheGAAdefciencywaslaterconfrmedbygeneticanalysis.Tegirldiedofcomplicationsdueto theclinicalpicturebeforestartingERT.Conversely,heryoungerbrotherhadtheopportunitytoreceiveanearlydiagnosisandthe rapidonsetofERT.Heisshowingaregressionofcardiachypertrophy. Conclusion.TeadventofERTimprovedclinicaloutcomes andsurvivalininfantile-onsetPD.Itsimpactoncardiacfunctionisstillunderstudy,butdiferentreportsintheliteraturehave shownencouragingdata.EarlyrecognitionofDGAAandpromptinitiationofERTisthereforecrucialtopreventtheprogression of the disease and improve the outcomes. 1.Introduction Lysosomal acid alpha-glucosidase (GAA, also called acid maltase) defciency (Pompe disease, formerly classifed as glycogenstoragediseasetypeII(GSDII))isarareautosomal recessive disorder with considerable allelic heterogeneity. It is caused by pathogenic variants in the gene for GAA. Defciency of GAA (DGAA) leads to the accumulation of glycogeninlysosomesandcytoplasm,whichresultsintissue destruction, most afecting the skeletal muscle [1, 2]. Infantile-onset DGAA is characterized by cardiomyopathy and severe generalized hypotonia. Without treatment, most patientsdiewithinthefrsttwoyearsoflife[3,4].Late-onset disease(juvenileandadultpresentation)ischaracterizedby skeletalmyopathy(usuallyinalimb-girdledistribution)and a protracted course leading to respiratory failure without cardiomyopathy [5]. Infantile-onset DGAA should be sus- pected in infants with profound hypotonia and cardiac insufciency [6, 7]. Juvenile or adult-onset DAA should be consideredinpatientswithprogressiveweaknessinalimb- Hindawi Case Reports in Pediatrics Volume 2023, Article ID 8470341, 5 pages https://doi.org/10.1155/2023/8470341