Carotid Structure and Function in MPS Syndromes: A Multicenter Study of the Lysosomal Disease Network

Mucopolysaccharidosis (MPS) syndromes are disorders characterized by enzyme deficiencies, and they have been linked to heart health complications. However, there are currently no proven markers of heart and artery health for this population. The main purpose of this observational study is to evaluate the ease and convenience of a non-invasive measurement of artery function in MPS I, MPS II and MPS VI patients compared to healthy control subjects. An observational study is a research design meaning that there is no treatment in this study. The research questions are: 1. Is the artery health of MPS I, II and VI patients different than healthy controls? 2. Is the artery health of MPS VI patients different than MPS I and II patients? It is hypothesized that MPS patients will have poorer outcomes of artery health compared to healthy controls.

Mucopolysaccharidosis (MPS) syndromes are disorders characterized by enzyme deficiencies. As a result of the enzyme deficiency, glycosaminoglycans that are normally recycled in a healthy individual cannot be degraded in the MPS patient. MPS syndromes have been linked to heart health complications. Complications related to coronary artery stenosis (narrowing) are recognized as potentially fatal sequelae of untreated and treated MPS. Presently, national guidelines are largely silent on coronary artery disease risk in this population. There are currently no validated markers of cardiovascular or coronary artery disease in the MPS population. The main purpose of this observational study is to evaluate the ease and convenience of a non-invasive measurement of artery function in MPS I, MPS II and MPS VI patients compared to healthy control subjects. Exploring the validity and usefulness of this non-invasive measurement is the first step towards developing validated markers of cardiovascular or coronary artery disease in the MPS population. Specific Aim #1: Compare carotid artery intima-media thickness and carotid stiffness in individuals with MPS I, II, and VI (treated and non-treated) vs. healthy age-and gender-matched controls. It is hypothesized that MPS patients will have increased carotid artery thickness and reduced carotid compliance and distensibility compared to healthy controls. Specific Aim #2: Compare carotid artery intima-media thickness and carotid stiffness in individuals with MPS VI vs. I and II and between MPS I patients clinically treated with HSCT vs. ERT. It is hypothesized that MPS VI will have decreased carotid thickness and increased carotid compliance and distensibility compared to MPS I and II and that MPS I patients treated with ERT will have increased carotid thickness and reduced carotid compliance and distensibility compared to MPS I patients treated with HSCT.