Carotid Structure and Function in MPS Syndromes: A Multicenter Study of the Lysosomal Disease Network
Condition: Mucopolysaccharidoses
MeSH terms: Mucopolysaccharidoses
Study type: Observational

Summary: 
      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.
    

Detailed description: 
      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.
    

Observational model: Case-Control
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        This is an observational study of 60 individuals with MPS I, II and VI between the ages of
        3 and 18. Those participating in this study will be seen for a onetime, one-hour study
        visit. Participants will be enrolled at the University of Minnesota, Minneapolis, Minnesota
        and Children's Hospital of Orange County, Orange, California.
      
Keywords: MPS I; MPS II; MPS IIIA; MPS VI