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OpenTrials
Active, Not Recruiting

NCT Number: NCT04946409

Burden of Disease and Functional Impairment in XLH

Observational study comprising prospective follow up as well as retrospective chart review in order to evaluate the longitudinal course of the disease in XLH patients with a specific focus on functional impairment, physical performance and complications associated with the disease or respective treatment.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

X Linked Hypophosphatemia Avitaminosis Bone Diseases Bone Diseases, Metabolic Calcium Metabolism Disorders Congenital, Hereditary, and Neonatal Diseases and Abnormalities Deficiency Diseases Familial Hypophosphatemic Rickets Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Genetic Diseases, Inborn Hypophosphatemia Hypophosphatemia, Familial Kidney Diseases Male Urogenital Diseases Malnutrition Metabolic Diseases Metabolism, Inborn Errors Metal Metabolism, Inborn Errors Musculoskeletal Diseases Nutrition Disorders Nutritional and Metabolic Diseases Phosphorus Metabolism Disorders Renal Tubular Transport, Inborn Errors Rickets Rickets, Hypophosphatemic Urogenital Diseases Urologic Diseases Vitamin D Deficiency

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Wuerzburg

Würzburg, 97074, Germany

About this study

This is an observational / non-interventional study in order to assess the longitudinal course of XLH including disease related burden of disease and functional impairment. This is accomplished by both prospective follow up of affected patients as well as retrospective chart review. Evaluation conducted as per clincal routine and specifically evaluated as part of this study will include

  • baseline documententation / demographic (as obtained from medical records)
  • general data on XLH-disease specific medical history
  • physical examination results
  • functional assessments
  • technical assessments
  • quality of life / questionnaires
  • laboratory evaluations

Who can participate

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male or female, aged ≥ 18 years, inclusive, at the time of enrollment
  • Diagnosis of X-linked Hypophosphatemia confirmed by
  • documented PHEX mutation in either the patient, or in a directly related family member
  • positive family history of XLH and symptoms of the disease or
  • Phosphaturia + elevated serum levels of c-term FGF23 or iFGF23 and symptoms of the disease
  • Written informed consent

Exclusion criteria

  • Suspected of confirmed diagnosis of another phosphate wasting disorder

Treatment and study plan

No intervention

Other

no intervention

Primary outcomes

  1. Course of disease

    Time frame: retrospective and up to 48 months from enrollment

    To document and assess the natural course of disease, associated symptoms and functional impairment in adult patients with XLH.

Secondary outcomes

  1. Comorbidities and medical treatment

    Time frame: retrospective and up to 48 months from enrollment

    Assess and document comorbidities and medical treatment regimens applied in adult patients with XLH

  2. Functional deficits and mobility constraints

    Time frame: retrospective and up to 48 months from enrollment

    Assess and document functional deficits and mobility constraints in adult patients with XLH

  3. Laboratory values

    Time frame: retrospective and up to 48 months from enrollment

    Assess laboratory parameters over time in adults with XLH

  4. Organ / tissue specific health issues

    Time frame: retrospective and up to 48 months from enrollment

    Describe frequency and outcome of organ / tissue specific health issues (affecting e.g. skeleton, dental health, muscles and joints) in adults with XLH

  5. Safety and tolerability of treatment

    Time frame: retrospective and up to 48 months from enrollment

    Evaluate safety and tolerability of various treatment regimens commonly applied in XLH patients

  6. Quality of life

    Time frame: retrospective and up to 48 months from enrollment

    Assess quality of life and respective determining factors in adults patients with XLH

Other outcomes

  1. Impact of treatment on physical performance

    Time frame: retrospective and up to 48 months from enrollment

    Evaluate the impact of clinical routine treatment including both medical approaches and physical therapy on physical performance and mobility of adult patients with XLH

  2. Medical history

    Time frame: retrospective and up to 48 months from enrollment

    Document and assess medical history of adult patients with XLH in order to understand its predictive value on burden of disease in adulthood

Sponsors and collaborators

Lead sponsor

Wuerzburg University Hospital

Other

Collaborators

  • Kyowa Kirin, Inc.

Registry information

Official study title

Identification of Longitudinal Burden of Disease and Functional Impairment in X-Linked Hypophosphatemia

Acronym: IdeFIX

Important dates

Study start
2020
Primary completion
2024
Study completion
2026
First posted
Jun 30, 2021
Registry last updated
Jul 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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