BACKGROUND: Mucopolysaccharidoses (MPS) are a group of lysosomal storage disorders caused by defects in genes coding for different lysosomal enzymes which degrade glycosaminoglycans. Impaired lysosomal degradation causes cell dysfunction leading to progressive multiorgan involvement, disabling consequences and poor life expectancy. Enzyme replacement therapy (ERT) is now available for most MPS types, offering beneficial effects on disease progression and improving quality of life of patients. The landscape of MPS in Europe is not completely described and studies on availability of treatment show that ERT is not adequately implemented, particularly in Southern and Eastern Europe. In this study we performed a survey analysis in main specialist centers in Southern and Eastern European countries, to outline the picture of disease management in the region and understand ERT implementation. Since the considerable number of MPS IVA patients in the region, particularly adults, the study mainly focused on MPS IVA management and treatment. RESULTS: 19 experts from 14 Southern and Eastern European countries in total responded to the survey. Results outlined a picture of MPS management in the region, with a high number of MPS patients managed in the centers and a high level of care. MPS II was the most prevalent followed by MPS IVA, with a particular high number of adult patients. The study particularly focused on management and treatment of MPS IVA patients. Adherence to current European Guidelines for follow-up of MPS IVA patients is generally adequate, although some important assessments are reported as difficult due to the lack of MPS skilled specialists. Availability of ERT in Southern and Eastern European countries is generally in line with other European regions, even though regulatory, organizational and reimbursement constrains are demanding. CONCLUSIONS: The landscape of MPS in Southern and Eastern European countries is generally comparable to that of other European regions, regarding epidemiology, treatment accessibility and follow up difficulties. However, issues limiting ERT availability and reimbursement should be simplified, to start treatment as early as possible and make it available for more patients. Besides, educational programs dedicated to specialists should be implemented, particularly for pediatricians, clinical geneticists, surgeons, anesthesiologists and neurologists.

1st Department of Pediatrics Hippokratio General Hospital Aristotle University Thessaloniki Greece

Archbishop Makarios 3 Hospital Nicosia Cyprus

Centre of Excellence for Reproductive and Regenerative Medicine Children's Hospital Zagreb Medical School University of Zagreb Zagreb Croatia

Clinic of Paediatrics Institute of Clinical Medicine Faculty of Medicine Vilnius University Vilnius Lithuania

Department of Child Neurology Epileptology and Social Pediatrics Centre for Rare Diseases University of Giessen Standort Giessen Feulgenstr 12 35389 Giessen Germany

Department of Clinical Genetics University Pediatric Hospital Sofia Bulgaria

Department of Paediatrics University Thomayer Hospital and 1st Faculty of Medicine Charles University Prague Czech Republic

Department of Pediatric Nutrition and Metabolic Diseases The Children's Memorial Health Institute Warsaw Poland

Department of Pediatrics General University Hospital and 1st Faculty of Medicine Charles University Prague Czech Republic

Department of Toxicology and Metabolic Diseases Heim Pal Children's Hospital Budapest Budapest Hungary

Faculty of Medicine University of Belgrade Belgrade Serbia

Institute for Sick Children Department of Pediatric Endocrinology and Metabolism Medical School University of Montenegro Podgorica Montenegro

Mother and Child Health Care Institute of Serbia Medical University of Belgrade Belgrade Serbia

National Institute of Children's Diseases Department of Paediatrics Medical Faculty Comenius University Centre for Inherited Metabolic Disorders Bratislava Slovakia

Neurogenetics Laboratory Neurology Department University Hospital of Heraklion University of Crete Heraklion Greece

Regional Centre of Medical Genetics INSMC Alessandrescu Rusescu Bucharest Romania

Unit of Rare Metabolic Diseases Department of Metabolic Diseases Jagiellonian University Medical College University Hospital Krakow Poland

University Children's Hospital Belgrade Serbia

University Children's Hospital Skopje North Macedonia

University Hospital Centre Zagreb Department of Internal Medicine Division of Metabolic Diseases Zagreb School of Medicine Zagreb Croatia

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