Active clinical trials for "Familial Hypophosphatemic Rickets"

The purpose of this prospective study is to characterize the natural history of ENPP1 Deficiency (including Generalized Arterial Calcification of Infancy Type 1 [GACI] and Autosomal Recessive Hypophosphatemic Rickets Type 2 [ARHR2]) and the early-onset form of ABCC6 Deficiency (Generalized Arterial Calcification of Infancy Type 2 [GACI-2]) longitudinally.

The purpose of the study is to gain a better understanding of the effect of iron on fibroblast growth factor 23 (FGF23) in the inherited disorder, autosomal dominant hypophosphatemic rickets (ADHR). ADHR is an inherited disorder in which the body makes too much FGF 23 and causes low blood phosphorus levels and bone problems such as rickets (bowed legs in children) or bone pain and weakness in adults. This study is to test whether or not giving iron helps correct the high FGF23 and there by correcting the phosphate problem.

X-linked hypophosphatemic rickets (XLH) is characterized by rickets, disproportionate short stature, impaired renal phosphate reabsorption and vitamin D metabolism. Despite oral phosphate and vitamin D treatment, most children with XLH demonstrate reduced adult height. The main objective of the study is to determine the beneficial effects of recombinant human growth hormone (rhGH) therapy on body proportions after 36 month in these patients. Secondary objective is to monitor side effects of the therapy.

X-linked hypophosphatemia (XLH) is the most common form of heritable rickets. Current treatments include active vitamin D metabolites (e.g. calcitriol) and phosphate salts. There is no consistent weight-based dosing of calcitriol and phosphate now. The primary objective of this study is to establish the efficacy of different dose of calcitriol combined with neutral phosphate in children with XLH.

In this prospective longitudinal cohort study we studied the efficacy and safety of burosumab in real-clinical practice for <13- and >13-years old children affected with X-linked hypophosphatemia. 57 children with XLH were switched from conventional treatment to burosumab. After 12 months we assessed the efficacy and safety of treatment with burosumab on the whole cohort and separately on the cohort of >13-years old adolescents.

Hereditary hypophosphatemia encompasses rare genetic conditions characterized by renal phosphate wasting. Increased circulating levels of fibroblast growth factor 23 (FGF23), a key regulator of phosphorus metabolism, are critical to the pathophysiology of these diseases, most notably in X-linked hypophosphatemia (XLH). Increased FGF23 induces hypertrophy and scarring in the heart in part via stimulating the traditional renin-angiotensin system (RAS) pathway, angiotensin-converting enzyme (ACE)/angiotensin (Ang ll), particularly in patients with chronic kidney disease, but the effect of FGF23 on the heart in patients with FGF23-related hypophosphatemic diseases is unknown. In addition, the relationship between FGF23 and the angiotensin-converting enzyme 2 (ACE2)/angiotensin-(1-7) (Ang-(1-7) pathway of the RAS is unknown. The objective of this study is to describe the relationship between FGF23, which causes low phosphorus levels, and components of the RAS in the blood and urine to help the investigators understand why the disease occurs and how to better treat it. Subjects will be identified by querying the Electronic Medical Record according to medical diagnosis. Thirty subjects, 2-24 years of age, will be recruited from the tertiary care Pediatric Endocrinology and Pediatric Nephrology clinics at Brenner Children's Hospital. Inclusion criteria include a confirmed diagnosis of hereditary FGF23-related hypophosphatemia. Clinical data will be obtained from the Electronic Medical Record. Each subject will undergo study assessments at baseline, 6 months and 1 year that include blood work, an echocardiogram, and blood pressure measurements. The primary hypothesis is that subjects with higher Ang-(1-7) levels have lower rates of cardiac hypertrophy and thus are protected against high FGF23 levels. The secondary hypothesis is that subjects with higher Ang-(1-7) levels have lower systolic blood pressure.

There is limited empirical data documenting disease progression and impact on quality of life for patients with X-linked hypophosphatemia (XLH). This study seeks to investigate the impact of XLH in adults living in the UK retrospectively and prospectively over a 12 month period, using qualitative interviews, SEIQoL-DW, EQ-5D-5L, SF36 quality of life tools. XLH is a rare, genetic, chronically debilitating and deforming condition (www.nice.org.uk/guidance/HST8). XLH is characterised by renal phosphate wasting, hypophosphatemia and defective bone mineralisation. The incidence of XLH is reported to be between 1:20,000 and 1:25,000 live births. In the UK, it is estimated that there are around 250 paediatric XLH patients and around 2,500 adult XLH patients (Delmestri,et al [Unpublished report]2018). The clinical phenotype of XLH is varied amongst patients, even among affected members of the same family. This can range from no signs or symptoms, slow growth in children, short stature, bone abnormalities that can affect movement and result in pain, bowed legs and knocked knees (where lower legs are positioned at an outward angle), tooth abscesses and excessive dental caries and hearing loss (adult patients only). This study will recruit 36 adults living with XLH, who are aged 28 years or over and living in the UK. The study will be advertised by the Sponsor and funder Medialis Ltd and via the patient organisation Metabolic Support UK. All study activities will take place via tele-visits and online questionnaires. The study will last approximately 2 years, allowing for one-year recruitment and a further 12 months to conduct all study visits.

Background: Generalized Arterial Calcification of Infancy (GACI) is a very rare disorder. It can be fatal before birth or by age 6 months. Anumber of people with GACI survive into adulthood. Those adults suffer from side effects of the disease, including rickets. It is unknown how common the disease Autosomal Recessive Hypophosphatemic Rickets Type 2 (ARHR2) is. It also has side effects. GACI and ARHR2 are usually caused by the mutations in the same gene. There are no approved treatments for the two diseases. Researchers want to study people with these diseases and their family members. This may help understand these rare and unique diseases better. The data could lead to new treatments for GACI and ARHR2. Objectives: To better understand the progression of GACI and ARHR2 and how genes might play a role in them. Eligibility: People with GACI or ARHR2, both living and deceased, and their parents and siblings. Design: Participants will allow researchers to access their medical records. They will give this consent by mail, email, or fax. Data will be taken from the records. Participants names will not be used. Instead, they will be identified by a code. Participants may give a blood sample. If a participant withdraws from the study, their data and samples will be destroyed. However, the coded clinical data in the official medical record and data in databases will NOT be destroyed. ...

Patients with X-linked hypophosphatemia (XLH) often report symptoms of fatigue and weakness particularly after exertion, in addition to their skeletal complaints. In previous trials using KRN23 (same drug as burosumab/Crysvita®), patients report these symptoms improve. The investigators wish to test this hypothesis directly by measuring muscle energy when patients begin treatment with Crysvita® for the first time.

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).