An observational study in Achondroplasia and Hypochondroplasia, sponsored by SYSNAV. Recruiting at 4 sites in 3 countries. Open to participants aged 2 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-09-23.
Sponsored by SYSNAV · Observational
The study aims to identify which Syde®-derived digital outcomes are reliable in FGFR3-related Skeletal Dysplasia. This requires to set-up a natural history study to measure limb movements in patients with ACH or HCH.
47 studies on the registry are indexed under Achondroplasia; 13 are open to participants now.
This study's planned enrollment of 140 is below the median of 200 across 19 observational studies indexed under Achondroplasia.
Browse Achondroplasia studies →SYSNAV is the lead sponsor of 5 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
France: Participants will be recruited from the patient registry of the Centre de Référence des Maladies Osseuses Constitutionnelles located at Necker Hospital / IMAGINE Institute. The APPT association (Association des Personnes de Petite Taille) will also help with the recruitment through flyers distribution. All visits will take place at Necker Hospital.
Belgium: Participants will be recruited from the Maladies Rares Génétiques Ostéo-articulaires (MaRGOs) patient registry located at Centre Hospitalier Universitaire (CHU) de Liège, with additional recruitment through Centre Hospitalier Régional (CHR) de Liège and support from the Solidarité Wallonne des Personnes de Petite Taille association through flyer distribution. All visits will take place at CHU de Liège and CHR de Liège.
United Kingdom: Participants will be recruited from the Site Research Waiting List
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
1.a. Aged 2 years old or older at the time of consent (France and Belgium)
Written obtained:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reliability of digital endpoint derived from Syde® assessed by the Intra-Class Correlation (ICC) for each recording period timepoint.
reliability assessed by the ICC (Intra-Class Correlation)for each recording period timepoint (baseline, 6 months, 12 months)
Time frame: 12 months
number of participants reaching 180 hours of recording during the recording periods defined in the protocol
Number of patients reaching 180 hours of recordings during the recording periods defined in the protocol (supposed optimal threshold for Syde®-derived digital endpoint computation) at baseline, 6 months, 12 months
Time frame: 12 months
System Usability Score (F-SUS) score at 6 months of Syde® use
System Usability Score (SUS) at 6 months. The System Usability Scale is a 10-item questionnaire . It is a simple tool to measure the usability of an interactive system and it is widely used. For each item, the user is asked to express their level of agreement or disagreement from 1 (strongly disagree) and 5 (strongly agree).
Time frame: 6 months
Correlation between digital endpoints derived from Syde® and 6-minutes walk test (6MWT)
Correlation at baseline and at different timepoints between Syde® derived digital endpoint and 6MWT
Time frame: 12 months
Correlation between digital endpoints derived from Syde® and growth parameters
Correlation at baseline and at different timepoints between Syde® derived digital endpoints and annualized growth velocity, height Z-score, body proportion ratios
Time frame: 12 months
Correlation between digital endpoints derived from Syde® and Patient-reported Outcomes (PROs)
Correlation at baseline and at different timepoints between Syde® derived digital endpoints and PROs
Time frame: 12 months
Longitudinal Change in digital endpoints derived from Syde®
Change from baseline in digital endpoints derived from Syde® at 6 and 12 months
Time frame: 12 months
Syde® movement reconstruction accuracy compared to Optical Motion Capture measures.
Stride detection accuracy of Syde®, stride length and stride velocity accuracy of Syde® and upper limb measures, compared to Optical Motion Capture measures
Time frame: Baseline
Qualitative interview exploring limitations on mobility and impact on daily life
caregiver and/or participant qualitative interview exploring limitations on mobility daily life
Time frame: baseline
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