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X-linked Hypophosphatemia and FGF21 (XLH 21)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03596554
Recruitment Status : Completed
First Posted : July 24, 2018
Last Update Posted : October 27, 2020
Information provided by (Responsible Party):
Hospices Civils de Lyon

Brief Summary:

Fibroblast Growth Factor 23 and Fibroblast Growth Factor 21 are two endocrine Fibroblast Growth Factors, requiring Klotho as a co-factor to promote their systemic actions. Fibroblast Growth Factor 21 is involved in the regulation of glucid and lipid metabolism. Fibroblast Growth Factor 21 Knock Out mice display obesity and hyperglycemia.

In investigators experience, patients with X-linked hypophosphatemia often present with early-onset over-weight that could be partly explained by decreased physical activity because of bone pains and deformations after puberty; however, patients usually display progressive over-weight earlier in life, when there is no limitation of physical activity yet.

To the knowledge of investigators the association between Fibroblast Growth Factor 23, Fibroblast Growth Factor 21 and Klotho in patients with X-linked hypophosphatemia has never been evaluated. Thus, the main objective of this study is to evaluate the glucid and lipid metabolism in patients with X-linked hypophosphatemia, the main working hypothesis being that the genetic deregulation in the Fibroblast Growth Factor 23 axis in patients with X-linked hypophosphatemia induces modifications of Klotho levels (namely decreased levels) that in turn will deregulate the Fibroblast Growth Factor 21 axis (resistance to Fibroblast Growth Factor 21 because of decreased Klotho levels).

Condition or disease Intervention/treatment
X-linked Hypophosphatemia Other: Descriptive study

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Study Type : Observational
Actual Enrollment : 39 participants
Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: X-linked Hypophosphatemia and Carbohydrate and Lipid Metabolism: a Role for FGF21?
Actual Study Start Date : January 11, 2019
Actual Primary Completion Date : February 27, 2020
Actual Study Completion Date : February 27, 2020

Intervention Details:
  • Other: Descriptive study
    Description of the circulating values of Fibroblast Growth Factor 21 in X-linked hypophosphatemia children compared to controls in the VITADOS cohort (healthy children and adolescents aged 10-18 years), after age-matched, pubertal stage and sex).

Primary Outcome Measures :
  1. Circulating FGF21 [ Time Frame: 1 day ]
    Samples specific to the study will be collected during a sampling performed as part of the usual care and follow-up of the patient. An additional tube (5 ml maximum) will be collected, which will be sent to the Lyon Sud Hospital Center for analysis of circulating FGF21.

Biospecimen Retention:   Samples Without DNA
Serum and plasma

Information from the National Library of Medicine

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Ages Eligible for Study:   10 Years to 18 Years   (Child, Adult)
Sexes Eligible for Study:   All
Sampling Method:   Non-Probability Sample
Study Population
Patients aged 10 to 18 years followed in the different sites of the French Reference Center for Rare Diseases of Calcium and Phosphate, and monitored for hypophosphatemic rickets; estimated number to be included, N=40

Inclusion Criteria:

  • Child with X-linked hypophosphatemia with PHEX gene mutation
  • Child between 10 and 18 years old
  • Child over 10 kg having a blood sample as part of the treatment (due to regulatory constraints for blood volume taken in 30-day period of 40 mL in children over 10 kg)
  • Child and parent / holder of parental authority who has been informed of the study and does not object to participate.

Exclusion Criteria:

- Pregnancy in progress

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03596554

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Centre de Référence des Maladies Rénales Rares - Centre de Référence des Maladies Rares du Calcium et du Phosphate - Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques - Hôpital Femme Mère Enfant
Bron, France, 69677
Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service d'Endocrinologie Pédiatrique - Hôpital du Kremlin Bicêtre
Paris, France, 94270
Endocrinologie, Maladies Osseuses, Gynécologie, Génétique, Hôpital des Enfants, CHU de Toulouse
Toulouse, France, 31059
Sponsors and Collaborators
Hospices Civils de Lyon
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Responsible Party: Hospices Civils de Lyon Identifier: NCT03596554    
Other Study ID Numbers: 69HCL18_0349
2018-A01304-51 ( Other Identifier: ID-RCB )
First Posted: July 24, 2018    Key Record Dates
Last Update Posted: October 27, 2020
Last Verified: October 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Familial Hypophosphatemic Rickets
Phosphorus Metabolism Disorders
Metabolic Diseases
Rickets, Hypophosphatemic
Bone Diseases, Metabolic
Bone Diseases
Musculoskeletal Diseases
Hypophosphatemia, Familial
Renal Tubular Transport, Inborn Errors
Kidney Diseases
Urologic Diseases
Metal Metabolism, Inborn Errors
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Calcium Metabolism Disorders
Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders