Clinical manifestations in Egyptian Pompe disease patients: Molecular variability and enzyme replacement therapy (ERT) outcomes.

Abstract

Background: Pompe disease is a rare genetic disorder caused by a deficiency of the enzyme acid alpha-glucosidase. This condition leads to muscle weakness, respiratory problems, and heart abnormalities in affected individuals.

Methods: The aim of the study is to share our experience through cross sectional study of patients with infantile-onset Pompe disease (IOPD) with different genetic variations, resulting in diverse clinical presentations. We evaluated their phenotype, genotype, radiological and laboratory findings including their cross-reactive immunologic material (CRIM) status. Infantile Pompe disease was diagnosed by measurement of the activity of the enzyme alpha-glucosidase. The diagnosis was confirmed by molecular genetic testing using PCR amplification and sequencing of the acid alpha-glucosidase (GAA) gene. Routine two-D echocardiography, and multi-parametric ECG-gated cardiac magnetic resonance imaging (CMR) were done to patients six months after starting enzyme replacement therapy (ERT).

Results: The results of our study revealed different genetic mutations among our patients, different CRIM status and also CMR abnormalities. CMR imaging revealed abnormalities in all cases that underwent the procedure, including myocardial and vascular changes, with feature tracking indicating issues across all parameters and LGE suggesting fibrosis. The patient with a positive immune response had the most severe cardiac abnormalities, despite improvements in muscle weakness and motor skills from ERT. This underscores that delayed diagnosis and ERT can lead to irreversible heart damage from autophagy buildup.

Conclusion: Pompe disease has various clinical presentations and results in significant CMR findings, which can be attributed to different genetic mutations. Early initiation of enzyme replacement therapy in infantile-onset Pompe disease is important to maximize its benefits.