Measuring limb movement in people with FGFR3-related skeletal dysplasia

Prospective Longitudinal Monocentric Study to Measure Limb Movement in Patients With FGFR3-related Skeletal Dysplasia Using Syde®

This project will try using Syde® wearable movement recordings to see which measurements reliably track limb movement in people aged 3 and older with achondroplasia or hypochondroplasia.

Quick facts

• Study type: Observational
• Enrollment: 40 (estimated)
• Ages: 3 Years to 65 Years
• Sex: All
• Sponsor: Sysnav (Industry-sponsored)
• Locations: 1 site (Paris)
• Trial ID: NCT07388966 on ClinicalTrials.gov

What this trial studies

This prospective, longitudinal monocentric project at Hôpital Necker will collect repeated limb movement recordings from people with FGFR3-related skeletal dysplasia using Syde® wearable technology. Participants aged 3 and older with genetically confirmed achondroplasia or hypochondroplasia who can walk at least 10 meters unassisted will wear devices and complete questionnaires during four-week recording periods every six months. The main aim is to identify which Syde®-derived digital outcomes are reliable and reproducible as natural history measures. Collected data will be analyzed for measurement reliability, feasibility of remote device use, and suitability as endpoints for future studies.

Who should consider this trial

Good fit: Ideal candidates are people aged 3 years or older with a genetically confirmed pathogenic FGFR3 variant causing achondroplasia or hypochondroplasia, who can walk unassisted for at least 10 meters and are willing to use wearable devices and complete study procedures.

Not a fit: People with short stature from other conditions, those with cognitive impairments that prevent device use or consent, or those unable to walk unassisted are unlikely to benefit from this project.

Why it matters

Potential benefit: If successful, the study could provide objective digital measures to monitor limb movement and disease course, improving how progression and treatment effects are tracked.

How similar studies have performed: Wearable digital outcomes have shown promise in other movement and neuromuscular conditions, but their use specifically in FGFR3-related skeletal dysplasia is still novel and largely unproven.

Eligibility criteria

Inclusion Criteria:

1. Aged 3 years old or older at the time of consent.
2. Written informed consent obtained:

   1. From the parent(s) or legal guardian(s) for participants under 18 years old.
   2. From participants 18 years old and older.
3. Affiliated to, or beneficiary of a social security category
4. Able to walk unassisted for at least 10 meters.
5. Genetically confirmed diagnosis with one pathogenic variant (ACMG class IV \& V) of achondroplasia or hypochondroplasia.
6. Participant (and caregivers for participants under 18 years old) willing and able to comply with all study procedures including: questionnaires, Syde® related procedures

Exclusion Criteria:

1. Subjects who have short stature condition other than ACH/HCH.
2. Presence of cognitive disorders that limit their understanding of the data collection process (training of device use and 4-week recording periods every 6 months, device return at the end of the study), the implication of the study and consent.
3. Presence or history of any concurrent disease or condition that could interfere with study participation, impact pediatric growth, affect motor or balance or gait function (such as neurological, endocrine, infectious, allergic, osteoarthritis, or inflammatory), assessed by the investigator.
4. Females who are pregnant, or planning to become pregnant during the study duration.
5. Body Mass Index = 35 kg/m2.
6. Recent upper and/or lower limbs injury (trauma/fracture or surgery) in the 6 months preceding inclusion.
7. Prior limb lengthening surgery or planned or expected to have limb lengthening surgery while enrolled in the study.
8. Presence of guided growth hardware (such as 8-plates) or planned orthopedic surgeries during the study.
9. Vulnerable patient (guardianship, curatorship or safeguarding of justice), unable to provide informed consent or who is unable to express their consent.

Where this trial is running

Paris

• Hopital Necker — Paris, France (Recruiting)

Study contacts

• Principal investigator: Genevieve Baujat — Hopital Necker
• Study coordinator: Ferial Toumi

Conditions Achondroplasia; Hypochondroplasia