Familial Hypocalciuric Hypercalcemia: Clinical Aspects and Evolution

Study Overview
=================
Brief Summary
-----------------
Familial hypocalciuric hypercalcemia (FHH) is a rare disease (ORPHA#405, www.orpha.net) and most likely underdiagnosed, that clinicians should be aware of in the differential diagnosis of a hypercalcemia. Appropriate identification of the FHH has implications in treatment and also for the family, since it is an automosal-dominant disease, due to mostly a heterozygous loss-of-function mutation of the CASR (calcium-sensing receptor) gene, but also much less freqüent mutations of another two genes (AP2S1 and GNA11). In case of clinical and biochemical suspicion of FHH, a genetic evaluation is mandatory. Nevertheless, an important number of patients, the genetic study is negative. This observational study is intended to perform a descriptive review of cases with clinical and biochemical suspicion of FHH who underwent a genetic study in the usual clinical practice. Clinical, biochemical and radiological characteristics, treatment, follow-up and comorbidities of genotype-negative participants will be compared with genotype-positive cases.

Official Title
-----------------
Familial Hypocalciuric Hypercalcemia: Clinical Aspects and Evolution

Conditions
-----------------
Familial Hypocalciuric Hypercalcemia

Intervention / Treatment
-----------------
* Other: Observational study. No intervention is performed


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with clinical and biochemical suspicion of FHH who, at the discretion of the physician in routine clinical practice, were asked to perform a genetic evaluation of FHH and whose genetic results are available. Exclusion Criteria: Genetic study of FHH is not available or was not performed despite clinical and biochemical suspicion of FHH.
Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Observational study. No intervention is performed|Descriptive study in participants with clinical and biochemical suspicion of FHH. Comparison between genotype-negative and genotype-positive participants with clinical and biochemical suspicion of FHH.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Age (years) | Clinical characteristics of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | 1 year | 
| Gender distribution (%) | Of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | 1 year | 
| Calcium levels (mg/dL) | Biochemical characteristics. Of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | Through study completion, an average of 1 year | 
| Parathyroid Ultrasound results | Of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment modalities used | Of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | 1 year | 
| FHH associated comorbidities | Of genotype-negative and genotype-positive participants with biochemical suspicion of FHH | Through study completion, an average of 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
hypercalcemia, Familial Benign Hypercalcemia, Familial hypocalciuric hypercalcemia