Cardiac involvement across mucopolysaccharidosis subtypes: insights from a longitudinal single-center study

OBJECTIVES: This study aimed to evaluate the pattern, extent, and progression of left- and right-sided cardiac involvement in patients with mucopolysaccharidosis followed in a single tertiary center. METHODS: 45 patients (24 males, 21 females) with enzymatically confirmed MPS (Types I, II, III, IV, and VI) followed between 2000 and 2018 were evaluated. Demographic data, consanguinity, clinical characteristics, electrocardiographic (ECG) and echocardiographic findings, and treatment data, including enzyme replacement therapy (ERT), were collected from medical records. Cardiac pathologies were characterized by echocardiography and chest radiography. RESULTS: The mean age at diagnosis was 6.64 ± 5.07 years. A high rate of consanguinity was observed: 73 % of parents had consanguineous marriages, including 40 % first-degree and 22.22 % second-degree. The most frequent cardiac findings were mitral insufficiency (53.3 %), and aortic insufficiency (35.6 %). ECG revealed sinus rhythm in all patients, with no conduction abnormalities. Mitral insufficiency was significantly more frequent in patients with pectus carinatum (100 vs. 40 % in those without pectus carinatum; p=0.023). Similarly, aortic insufficiency was significantly more frequent in patients with kyphoscoliosis (63.64 vs. 23.81 %; p=0.027). CONCLUSIONS: Cardiac involvement is frequent and clinically significant in MPS. The left-sided cardiac pathology did not deteriorate during follow-up, whereas progression was observed in right-sided cardiac involvement. Regular, systematic cardiac evaluation is essential in all MPS subtypes. The findings also underscore the importance of genetic counseling in populations with high consanguinity to improve early diagnosis and guide long-term management strategies.