Clinical and Molecular Features of Our Pompe Patients: Single-Center Experience

Abstract

Introduction: Pompe disease (PD), glycogen storage disease Type II (GSD II), is an autosomal recessive inherited lysosomal storage disease caused by pathogenic variants in the GAA gene that encodes lysosomal acid alpha-glucosidadase (GAA) enzyme. The incidence of the disease varies from country to country. PD is mainly presents as two groups of phenotypes as infantile-onset Pompe disease (IOPD) and late-onset Pompe disease. Objective: The aim of this study is to discuss the molecular and clinical characteristics of infantile-onset Pompe disease (IOPD) and late-onset pompe disease (LOPD) followed-up in our center. Method: A total of 10 patients diagnosed with IOPD and 4 patients diagnosed with LOPD in Izmir Dr. Behcet Uz Pediatric Health and Diseases and Surgery Training and Research Hospital Pediatric Metabolism Unit between 06.01.2015 and 06.01. 2019 were included in the study. The patients' demographic characteristics, clinical findings at the time of diagnosis and during the folllow-up period, biochemical findings, muscle biopsy data, results of enzymatic analyses and molecular-genetic characteristics were recorded retrospectively. Results: A total of 10 patients were included in the study. 7 patients were diagnosed with IOPD and 3 patients with LOPD. The median follow-up period of all patients was 26 months (range: 6-42 months). The c.896 C> T (8/32, 25%) is detected as the most common variant. 1237G>T (p.Asp413Tyr), c.2019 C>A (p.Asn673Lys), c.418A>T (p.Asn140Tyr) variants were detected for the first time. Conclusion: Pompe disease is one of the most important congenital metabolic diseases in which early diagnosis and treatment are of great importance. Despite the significant improvement in disease prognosis with the introduction of enzyme replacement therapy, there are still patients with poor prognosis despite early diagnosis. Phenotype-genotype studies are crucial in this respect.