This study's investigators previously demonstrated the potential utility of non-invasive carotid ultrasonography to calculate carotid intima media thickness (cIMT) and stiffness (as measured by the three parameters, carotid cross-sectional distensibility \[cCSD\], carotid cross-sectional compliance \[cCSC\], and carotid incremental elastic modulus \[cIEM\]) in people with mucopolysaccharidoses (MPS). Investigators also studied arterial gene expression in animal models of MPS, and identified upregulation of a number of markers potentially tied to atherosclerosis and inflammation. These include the atherosclerotic marker known as Clusterin (CLU), Cathepsin S, Elastin, and the inflammatory cytokines interleukin 1-α, interleukin 1-β, interleukin 2, and interleukin 6. Other studies have identified elevation in circulating tumor necrosis factor-α correlating with pain and physical disability in certain mucopolysaccharidoses. Since these studies are cross sectional, and not longitudinal, this study aims to annually measure these previously studied biomarkers (carotid measurements, circulating cytokines, cathepsin S, elastin, and CLU) in a large cohort of MPS patients. This study is a 3-year, prospective, anonymized, longitudinal assessment of cardiovascular structure, function, and circulating biomarkers in patients with mucopolysaccharidoses.