An observational study in Hypochondroplasia, sponsored by QED Therapeutics, a BridgeBio company. Recruiting at 25 sites in 10 countries. Open to participants aged 30 Months to 16 Years. Per ClinicalTrials.gov, last updated 2026-07-16.
Sponsored by QED Therapeutics, a BridgeBio company (part of BridgeBio) · Observational
This is a long-term, multicenter, non-interventional study of children ages 2.5 to \<17 years with hypochondroplasia (HCH).
The objective is to evaluate growth, HCH-related medical complications, health-related quality of life, functional abilities and cognitive functions of study participants. Data collected will contribute to the characterization of the natural history of children with HCH. No study medication will be administered.
101 studies on the registry are indexed under Mucopolysaccharidosis IV; 27 are open to participants now.
This study's planned enrollment of 150 is above the median of 100 across 41 observational studies indexed under Mucopolysaccharidosis IV.
Browse Mucopolysaccharidosis IV studies →QED Therapeutics, a BridgeBio company is the lead sponsor of 8 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Children with hypochondroplasia
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.
Signed .
Aged 2.5 to \<17 years at study entry.
Diagnosis of HCH documented clinically by the presence of disproportionate short stature and confirmed with a molecular test.
Participants are ambulatory and able to stand without assistance.
Study participants and parent(s), guardian(s), or caregiver(s) are willing and able to comply with study visits and study procedures.
Exclusion Criteria:
Have ACH or short stature condition other than HCH.
In females, having had their menarche. Annualized height growth velocity ≤1.5 cm/year over a period ≥6 months prior to screening.
Having a disease or condition that in view of the investigator or Sponsor will interfere with the evaluation of growth, with study participation or not be in the best interest of the participant.
Clinically significant abnormality in any laboratory test result at screening
Current evidence of corneal or retinal disorders.
Have used any other or approved product or medical device for the treatment of HCH or short stature for ≥ 30 days or with the last dose \<6 months before screening.
Have had regular long-term treatment (>1 month) with oral (low-dose ongoing inhaled steroid for asthma is acceptable).
Previous limb-lengthening surgery or guided growth surgery with plates still in place or removed within the 6 months prior to screening.
Having had a fracture of the long bones or spine within 12 months of screening.
History and/or current evidence of extensive ectopic tissue calcification.
History of .
Concurrent circumstance, disease, or condition that, in the view of the investigator and/or sponsor, would interfere with study participation, and/or would place the participant at high risk for poor compliance with study activities or for not completing the study.
Current participation in any other ongoing clinical study with another sponsor.
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.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
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.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Annualized height velocity
Time frame: up to 3 years
Change over time in height Z-score, upper arm to forearm ratio, and upper leg to lower leg ratio
Time frame: up to 3 years
Cognitive functions
Time frame: up to 3 years
HCH-related medical events reported as medical history or NT-AEs
Time frame: up to 3 years
HCH-related surgical procedures
Time frame: up to 3 years
Change from BL in the Physical Functioning dimension of the Pediatric Quality of Life Generic Core Scale Short Form.
Scale scores 0-100. Higher score=better Health-Related Quality of Life
Time frame: up to 3 years
Change from BL in collagen X marker concentration (ug/L).
Time frame: up to 3 years
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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QED Therapeutics, a BridgeBio company →