ClinicalTrials.gov record NCT07712003

Natural History to Assess Disease in Patients With MPS IIIC

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Jul 27, 2026

Observational Study to Assess Disease Symptoms and Progression in Participants With Sanfilippo Syndrome Type C (Mucopolysaccharidosis Type III [MPS III] C)

StatusNot yet recruitingThe study has been registered but has not started enrolling. Sites and contacts may not be listed yet.
Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.
Age1 year old to 25 years old
SexAll
LocationUnited States
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

A remote, prospective observational study that collects home videos and caregiver questionnaires from people with confirmed MPS IIIC. Assessments occur at baseline and every 6 months for two years (five time points total). About 35 participants aged 1–25 will be enrolled. No investigational drug or procedure is given as part of this study.

What it is studying. The study is measuring symptoms and how they change over time in people with MPS IIIC by using caregiver-recorded videos and electronic observer-reported questionnaires, then scoring functional, language, speech, behavior, and mobility changes.

What the researchers hope to learn. To describe disease symptoms and progression in MPS IIIC over time; to measure daily living skills, language, speech, behavior, and mobility using videos and questionnaires; and to generate natural-history data that may inform future research and drug development.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

This is a REMOTE prospective observational study of participants with MPS IIIC. No investigational medicinal product will be administered as part of this study. Patients functional abilities will be captured using video recordings taken by patients legal representative or caregiver using a dedicated clinical video application downloaded from the internet onto a smartphone. The video application is called C-RARE. Electronic observer-reported outcome (ObsRO) questionnaires will be completed by the legal representatives or caregivers via C-RARE. The study will last two years with videos and questionnaires taken every 6 months for a total of 5 time points. Data will then be reviewed and measured for functional change using a scoring scale designed for the use of this study.

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • ≥1 year and ≤ 25 years of age 2. Confirmed diagnosis of MPS IIIC by all of the following:
  • Deficiency in the Hgsnat enzyme activity
  • Genetic analysis demonstrating homozygous or compound heterozygous, pathogenic, and/or potentially pathogenic variants in the Hgsnat gene
  • Signs/symptoms consistent with MPS IIIC, or individuals who have not presented with signs/symptoms of disease but meet inclusion criteria 2a and 2b 3. Electronic informed consent from legal representative(s) or caregivers and when possible, pediatric or adult assent from the participant 4. One of the legal representative(s) or the caregivers is willing to perform at home visits and assessments per instruction 5. Ability to comply with protocol requirements, in the opinion of the Investigator 6. Able to take food or liquid by mouth, able to walk with or without assistance 7. Participants must have health insurance 8. Caregiver willing and able to comply with protocol requirements, including performing at-home visits and assessments 9. Participants must have smart phone or tablet and reliable internet connection 10. Have one of these languages as their first language: English, Spanish, French, German or Portuguese

Exclusion criteria

  • Have received prior gene therapy or ERT for the treatment of MPS IIIC ever or any other investigational drug for any reason within 30 days prior to the Screening visit (Visit 1)
  • Have concomitant illness or medical condition that, in the opinion of the Investigator, might compromise the participant's ability to comply with protocol requirements or the participant's wellbeing or safety, or the interpretability of the participant's clinical data

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

The study will be conducted remotely; no in-person visits are required. Approximately 35 participants with MPS IIIC will be enrolled in the study through a study site in the United States of America (USA). Enrollment of the first 25 participants with age ≤10 years will help ensure that the data collected from these younger participants will provide a better understanding of the early phase of the disease that may be relevant for future drug development. The remaining 10 participants will be between 11 to 25 years of age. The cutoff for the study is 25 years old. Participants speaking either Spanish, Portuguese, German, French or English may enroll in the study. At Screening (Visit 1), the site coordinator based at UT Southwestern will review the laboratory report with a confirmed diagnosis of Hgsnat-deficiency MPS IIIC and a mutational analysis report demonstrating homozygous or compound heterozygous, pathogenic, and/or potentially pathogenic variants in the Hgsnat gene to assess the eligibility of the participants. After confirming diagnosis by the site coordinator, the caregiver or legal representative(s) will read and sign the informed consent form electronically, and when possible, the participant will provide adult or pediatric assent electronically. At Baseline (Visit 2), the legal representative(s) or caregiver will be asked to complete electronic demographics and medical record questionnaire via the C-RARE App. At Baseline (Visit 2) and at 6-month intervals (from Visit 3 through the end of the study), the legal representative(s) or caregiver will be asked to complete questionnaires and record home video assessments using a dedicated study app called C-RARE. Functional and cognitive abilities will be captured in the home environment by video and PEDI-CAT, an electronic a caregiver reported outcome assessment. The legal representative(s) or caregiver will be provided with a C-RARE kit (via mailing), which includes a manual and props, as well as training for using the app. Baseline at-home visit (demographics, medical/surgical history, concomitant medications/therapy history, video and PEDI-CAT assessment, and ObsRO) should be completed at Visit 2. At-home Visit 3 to Visit 6 (video, PEDI-CAT assessment, and ObsRO) should be completed within a 14-day period for each visit. The legal representative(s) or caregiver will be provided with the timeline for each visit. The study population will include participants with a confirmed diagnosis of MPS IIIC. Participants will be recruited for approximately 3 months by patient organizations. The patient organizations will provide participants with details of the site coordinator at UTSW. Participant-level data will be obtained through C-RARE app and PEDI-CAT.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This is a fully remote, two-year study with no investigational drug given. At screening the site coordinator will review the participant's lab and genetic reports. Caregivers will give electronic consent, receive a mailed C-RARE kit and training, then use the C-RARE app to record home videos and complete electronic caregiver questionnaires (including PEDI-CAT and other observer-reported outcomes) at baseline and every 6 months for a total of five time points. Home assessments should be completed within specified windows (about 14 days) and the study team will review the submitted videos and questionnaires.

How the study is structured. This is a remote, prospective observational (case-only) study. Caregivers use a dedicated smartphone/tablet app (C-RARE) to submit scheduled home videos and complete electronic questionnaires (including PEDI-CAT and behavior surveys) at baseline and every 6 months for up to two years. Diagnosis must be confirmed from laboratory and genetic reports before enrollment. No treatments are assigned; data are reviewed centrally using a study-specific scoring scale.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
  • The registry says recruitment has not started. When is it expected to open, and can I register interest now?
  • The listed sites are in United States. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on Sanfilippo syndrome

Clinical trials12 trials listed for Sanfilippo syndromeEvery trial the registry lists for Sanfilippo syndrome, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in Sanfilippo syndrome researchLatest monthly update: September 2026. Includes: Approved drug shortlist. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Nov 1, 2026 (estimated)
Primary completion
Nov 1, 2028 (estimated)
Study completion
Feb 1, 2029 (estimated)
Target enrollment
35 participants (estimated)
Last updated on registry
Jul 17, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Phoenix Nest
Collaborators
  • National Institutes of Health (NIH)

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

Terms used on this page · explanations by MedicalUpdates.ai

investigational
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
legal representative
A person who is legally allowed to make decisions, including consent to research, on behalf of someone who cannot consent for themselves.
inclusion criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
assent
A child's or dependent adult's agreement to take part, given alongside the formal consent of a parent or legal representative.
Screening visit
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
Enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
Baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
concomitant medications
Other medicines a participant takes during the study. Some must be reported; some are restricted.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this website; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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