An observational study in PIK3CA-related Overgrowth Spectrum, CLOVES Syndrome and Klippel Trenaunay Syndrome, sponsored by Institut National de la Santé Et de la Recherche Médicale, France. Completed at 1 site in France. Per ClinicalTrials.gov, last updated 2026-02-23.
Sponsored by Institut National de la Santé Et de la Recherche Médicale, France · Observational
Overgrowth syndromes are rare genetic disorders defined by tissue hypertrophy that can be either localized or generalized, affecting both latitudinal and longitudinal growth. The genes involved in overgrowth syndromes are not well characterized but mostly concern the PIK3CA/AKT/mTOR pathway, a major actor of cell growth and proliferation. The mutations are not inherited but occurs during embryogenesis leading to somatic mosaicism. Owing to the variability of the clinical presentation, their exact prevalence is yet unknown. In order to answer this question, the investigators team create here the first French national registry on overgrowth syndromes.
Overgrowth syndromes are rare genetic disorders defined by tissue hypertrophy that can be either localized or generalized, affecting both latitudinal and longitudinal growth. The genes involved in overgrowth syndromes are not well characterized but mostly concern the PIK3CA/AKT/mTOR pathway, a major actor of cell growth and proliferation. The mutations are not inherited but occurs during embryogenesis leading to somatic mosaicism. Owing to the variability of the clinical presentation, their exact prevalence is yet unknown. In order to answer this question, the investigators team create here the first French national registry on overgrowth syndromes.
8 studies on the registry are indexed under Klippel-Trenaunay-Weber Syndrome; 4 are open to participants now.
Browse Klippel-Trenaunay-Weber Syndrome studies →Institut National de la Santé Et de la Recherche Médicale, France is the lead sponsor of 378 studies on the registry; 81 are open to participants now.
Counted across the registry records on this site, refreshed daily.
All patients with overgrowth syndrome referred by their doctors or patients who have sent a consultation request to the Reference Center (https://hopital-necker.aphp.fr/contacts-cloves) will be enrolled.
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.
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.
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.
The investigators will collect demographic, clinical, biological and imaging characteristics of patients with PROS.
Description of patients with overgrowth syndromes
Clinical and molecular characterization of patients with overgrowth syndromes will be performed.
Time frame: 5 years
Prevalence of overgrowth syndromes in France
An estimation of the prevalence of overgrowth syndromes in France will be done
Time frame: 5 years
Biobanking of samples derived from patients with overgrowth syndromes
A biobank will be created with biological samples (plasma) collected for research and residual biological samples from patient cares (treatment/diagnosis)
Time frame: 5 years
Description of patient cares: mumber of consultations and hospitalizations, number of treatment lines, grouping of patients by type of course (clusters)
An analysis of care trajectories will be performed. These data will be collected from health insurance databases for patients with overgrowth syndromes.
Time frame: 5 years
Economic evaluation of cares for patients with overgrowth syndromes: cost of care, per period and cumulative.
SDNS data will be used to estimate care costs per year for patients with overgrowth syndrome.
Time frame: 5 years
Plan to share: No
This study is completed, as verified in Apr 2023. You cannot join it, but the record below documents what was studied.
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