Prospective, Longitudinal, Observational Registry of Adult Patients With Hypophosphatasia (REG-HYPO)

Study Overview
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Brief Summary
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The purpose of this study is to assess medical events during follow-up of adult patients having hypophosphatasia and consulting rheumatologists.

Detailed Description
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Hypophosphatasia (HPP) is a rare inherited disease caused by mutations of the ALPL gene. In adult HPP, patients may suffer from fractures, pseudofractures, fracture healing complications, osteoarthritis, chondrocalcinosis, dental diseases, muscle pain and disability, but also headache, muscle weakness, ocular disease, and other symptoms. In some cases the diagnosis is severely delayed. Moreover a number of patients having such symptoms and a low level of serum alkaline phosphatase, without gene mutation can be followed by rheumatologists with difficulties in management of bone fragility and pain. The aim of this register is to describe prospectively the medical events in adult patients having hypophosphatasia, whether or not there is a proven genetic abnormality.

Official Title
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Prospective, Longitudinal, Observational Registry of Adult Patients With Hypophosphatasia

Conditions
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Hypophosphatasia

Intervention / Treatment
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* Other: Data collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: men and women, aged 18 and over, with no upper age limit, who have had a total alkaline phosphatase value of less than 40 IU/l on at least 3 occasions, with at least one rheumatological symptom. Exclusion Criteria: transient hypophosphatasia: absence of confirmation of a value below 40 IU/l on at least 3 samples, secondary hypophosphatasia according to the expert rheumatologist (drugs, endocrine disease, other genetic disease...).

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Data collection|Collection data from diagnostic Data collected following to medical exam as part of care|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characterise the circumstances of diagnosis, and deduce ways to reduce the diagnostic delay of hypophosphatasia in adults. | Time since first symptom due to hypophosphatasia | At inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characterise non bony forms: chondrocalcinosis, multiple tendon calcifications, inflammatory pseudo-rheumatism, odonto-HPP | Proportion of each of the non-bone forms in the diagnosed population. | At inclusion | 
| Characterise the forms for which the genetic analysis is negative | Proportion of patients with clinical hypophasphatasia, without genetic evidence. | At inclusion | 
| Recognise situations of associated osteoporosis. | Proportion of patients with femoral and/or spinal densitometric osteoporosis. | At 72 months | 
| Characterise the practical follow-up of asfotase alpha treatment started in adults | Maintenance of enzyme replacement therapy. | At 72 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cohort, Hypophosphatasia, Bone fragility, Enthesopathy, Asfotase