Osteoporosis in RETT Syndrome (OSRETT)

April 2, 2026 updated by: Assistance Publique - Hôpitaux de Paris

Osteoporosis in RETT Syndrome. Understanding the Mechanisms and Identification of Biomarkers.

Based on our clinical observations, many girls with RETT syndrome, a severe neuro-developmental encephalopathy, suffer from osteoporosis which can appear at a very early age (before age 10) and can lead to fractures, pain and a limitation in mobility. Few epidemiological studies have estimated the frequency of osteoporosis in girls with RETT syndrome and showed that they are more exposed then children with other neuro-developmental diseases with a same degree of neurological handicap. However, the mechanisms that lead to early osteoporosis in RETT syndrome remain unknown. Mutations in the MECP2 gene are found in 95% of RETT patients and preliminary experimental studies have shown that this can lead to abnormal expression of the gene that codes for osteoprotegerin, a protein implicated in bone remodelling by interacting with RANK-ligand.

In order to identify risk factors of osteoporosis in RETT syndrome and to understand the pathophysiological mechanisms the study protocol includes:

  1. Clinical evaluation of bone health (history of bone fractures, pain, nutritional status, pubertal stage, daily caloric/calcium intake, anti-epileptic drugs, walking ability, vitamin D satus)
  2. evaluation of the mineral density at the lumber spine using DEXA
  3. measuring concentrations of osteoprotegerin and RANK-ligand

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Based on our clinical observations, many girls with RETT syndrome, a severe neuro-developmental encephalopathy, suffer from osteoporosis which can appear at a very early age (before age 10) and can lead to fractures, pain and a limitation in mobility. Few epidemiological studies have estimated the frequency of osteoporosis in girls with RETT syndrome and showed that they are more exposed to osteoporosis then children with other neuro-developmental diseases with a same degree of neurological handicap. However, the mechanisms that lead to early osteoporosis in RETT syndrome remain unknown.

Mutations in the MECP2 gene are found in 95% of RETT patients. Preliminary experimental studies on the transcriptional consequences of MECP2 mutations showed that the expression of 13 genes were significantly dysregulated and one of them is the gene that codes for osteoprotegerin, a soluble receptor that binds to RANK-ligand. RANK-ligand is an osteoclastic differentiation factor expressed by osteoblasts.

In order to identify risk factors of osteoporosis in RETT syndrome and to understand the pathophysiological mechanisms the study protocol includes:

  1. Clinical evaluation of bone health (history of bone fractures, pain, nutritional status, pubertal stage, daily caloric/calcium intake, anti-epileptic drugs, walking ability, vitamin D status)
  2. evaluation of the mineral density at the lumber spine using DEXA
  3. measuring concentrations of osteoprotegerin and RANK-ligand

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
98

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Bicêtre, France, 94275
        • Kremlin bicêtre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

5 years to 45 years (Child, Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • RETT syndrome
  • MECP2 mutation

Exclusion Criteria:

  • no identified MECP2 mutation
  • history of drugs that interfere with bone metabolism

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Other: RETT patients
Other: biological markers and evaluation of the mineral density at the lumber spine using DEXA

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
osteoporosis in RETT patients
Time Frame: Day 0
Correlation between clinical/biological risk factors and mineral density and osteoporosis in RETT patients
Day 0

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Biological Mechanisms of osteoporosis
Time Frame: Day 0
RANK-ligand and osteoprotegerin concentrations
Day 0

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Assistance Publique - Hôpitaux de Paris

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
URC-CIC Paris Descartes Necker Cochin

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Agnès Linglart, MD, PhD, Kremlin Bicêtre hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 10, 2009

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 6, 2014

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 6, 2014

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 2, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2014

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 10, 2014

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • P071230

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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