Enthesopathies are the determinant of a poor quality of life in adults with X-linked hypophosphatemia (XLH).
To describe the prevalence of patients with enthesopathies and to identify the risk ...factors of having enthesopathies.
Retrospective study in the French Reference Center for Rare Diseases of the Calcium and Phosphate Metabolism between June 2011 and December 2020. Adult XLH patients with full body X-rays performed using the EOS® low-dose radiation system and clinical data collected from medical records. The main outcome measures were demographics, PHEX mutation, conventional treatment, and dental disease with the presence of enthesopathies.
Of the 114 patients included (68% women, mean age 42.2 ± 14.3 years), PHEX mutation was found in 105 patients (94.6%), 86 (77.5%) had been treated during childhood. Enthesopathies (spine and/or pelvis) were present in 67% of the patients (n = 76). Patients with enthesopathies were significantly older (P = .001) and more frequently reported dental disease collected from medical records (P = .03). There was no correlation between the PHEX mutations and the presence of enthesopathies. Sixty-two patients had a radiographic dental examination in a reference center. Severe dental disease (number of missing teeth, number of teeth endodontically treated, alveolar bone loss, and proportion of patients with 5 abscesses or more) was significantly higher in patients with enthesopathies.
Adult XLH patients have a high prevalence of enthesopathies in symptomatic adults patients with XLH seen in a reference center. Age and severe dental disease were significantly associated with the presence of enthesopathies.
Hypoparathyroidism in children is most often due to mutations in genes involved in parathyroid development and calcium homeostasis signaling. Some rare cases result from autoimmune attack on the ...parathyroid glands as a part of the type 1 polyglandular failure syndrome (autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy). The majority of cases of pediatric hypoparathyroidism are well controlled under conventional treatment with calcium and vitamin D analogs. However, this treatment may be difficult to manage, especially in two situations: 1) in the context of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy and 2) activating mutations in the calcium-sensing receptor. We successfully treated three patients with hypoparathyroidism with continuous subcutaneous administration of rhPTH1-34 (recombinant human PTH1-34), two of which were refractory to conventional therapy.
About 8% of children born small for gestational age (SGA) do not reach a final height within the normal range. Recombinant human growth hormone (rhGH) has been shown to be effective in increasing the ...final height in children born SGA. Our objective was to identify predictive factors of final height in children born SGA treated with rhGH.
In this retrospective study, conducted in a tertiary pediatric endocrinology referral center, we recruited all patients born SGA (defined as birth length or weight <10th percentile) treated with rhGH for more than 12 months for whom final height data were available. Some patients had received gonadotropin-releasing hormone (GnRH) analog therapy.
We included 252 patients with an average birth length of -2.0 ± 0.7 SD and birth weight of -1.7 ± 1.0 SD. After 4.6 ± 2.8 years of rhGH treatment, their height increased from -2.2 ± 0.9 SD to -1.5 ± 0.9 SD. In multivariate analysis, we identified 8 factors that predict 46% of the final height, namely, cause of SGA (p < 0.0001), GnRH analog therapy >2 years (p = 0.006), birth length (p < 0.02), height at the start of rhGH (p < 0.0001), IGF-1 level at the start of rhGH (p = 0.0002), growth velocity during the 1st year of treatment (p = 0.0002), and age and height at the onset of puberty (p < 0.0001, p = 0.0007, respectively).
In this large cohort of SGA patients who had reached their final height, we were able to confirm that growth hormone increases final height in short SGA children. In addition, we identified several factors associated with a better response to growth hormone treatment.
Context: Mutations in the cathepsin K gene (CTSK) cause a very rare form of short-limb dwarfism called pyknodysostosis (online inheritance in man 265800) that reduces adult height to 130–150 cm.
...Objective: To study the effects of GH in children with pyknodysostosis.
Design and Methods: This was a pilot open study of three children with pyknodysostosis (P1, P2, P3) and 16 age-matched children with idiopathic short stature (ISS) treated with a similar IGF-I-based dosing of GH therapy. P1, P2, and P3 received a mean GH dose of 29, 67, and 120 μg/kg · d, respectively, during 12, 6.5, and 5 yr, whereas the ISS group received a mean dose of 62 ± 21 μg/kg · d during 5.4 ± 2 yr.
Results: P1, P2, and P3 had the typical clinical and radiological features of pyknodysostosis. They were shown to carry three different homozygous missense mutations of the CTSK gene. After onset of GH at 4.5, 5.4, and 10.9 yr of age, respectively, height increased from −2, −4.2, and −3 sd score to −1, −0.5, and −1 sd score after a 12, 6.5, and 5 yr GH treatment. Remarkably, body disproportion was largely corrected by GH treatment. IGF-I levels in P1, P2, and P3 were within the range of the ISS group.
Conclusions: Pyknodysostotic patients can reach near-normal stature and skeletal proportions with a personalized GH treatment targeted at appropriate IGF-I levels. Given the severity of this rare dwarfism, we propose that GH should be offered to affected children.
Given the severity of pycnodysostosis, a rare form of dwarfism, it is proposed that GH should be offered to affected children, but long-term safety data should be collected.
Pseudohypoparathyroidism (PHP, OMIM #103580) is a very rare disease (incidence 0.3-1/100,000). Heterozygous inactivating mutations involving the maternal GNAS exons 1-13 that encodes the alpha ...subunit of the stimulatory G protein (Gsα) cause inactivating parathyroid hormone (PTH)/PTHrP signalling disorder type 2 (iPPSD2 or PHP type 1A), which is characterized by Albright hereditary osteodystrophy and resistance to multiple hormones that act through the Gsα signalling pathway (including PTH, thyroid-stimulating hormone, and α-melanocyte-stimulating hormone). To date, little information is available on craniofacial features in patients with PHP. The small number of patients studied in previous reports as well as the lack of molecular characterization of the patients may have precluded the detection of specific orofacial manifestations in the different PHP subtypes.
We conducted a systematic analysis of dental and craniofacial features in 19 patients with iPPSD2 and maternal GNAS inactivating mutations to assess the frequency and specificity of the anomalies.
Facial examinations showed reduced vertical, sagittal, and transverse development of the mid-facial structures. Intraoral and radiographic examinations revealed that 89 per cent of the patients had at least one dental anomaly, including tooth submergence leading to severe infraocclusion in 83 per cent of cases. Craniofacial analysis of lateral cephalometric radiographs also showed a significant alteration in the development of the cranial base and maxillary and mandibular structures in these patients.
Patients with iPPSD2 and maternal GNAS mutations had specific craniofacial alterations and dental abnormalities. These specific defects should be assessed in order to provide appropriate dental and orthodontic care to these patients. (clinical trial registration: 1920371 v 0, French Nationale Data Processing and Liberties Commission - CNIL).
Autoimmune polyendocrine syndrome type-1 (APS-1) is caused by mono- or biallelic loss-of-function variants of the autoimmune regulator gene
AIRE
underlying early-onset multiorgan autoimmunity and the ...production of neutralizing autoantibodies against cytokines, accounting for mucosal candidiasis and viral diseases. Medical intervention is essential to prevent or attenuate autoimmune manifestations. Ruxolitinib is a JAK inhibitor approved for use in several autoimmune conditions. It is also used off-label to treat autoimmune manifestations of a growing range of inborn errors of immunity. We treated three APS-1 patients with ruxolitinib and followed them for at least 30 months. Tolerance was excellent, with no medical or biological adverse events. All three patients had remarkably positive responses to ruxolitinib for alopecia, nail dystrophy, keratitis, mucosal candidiasis, steroid-dependent autoimmune hepatitis, exocrine pancreatic insufficiency, renal potassium wasting, hypoparathyroidism, and diabetes insipidus. JAK inhibitors were therefore considered an effective treatment in three patients with APS-1. Our observations suggest that JAK/STAT pathways are involved in the pathogenesis of APS-1 autoimmune manifestations. They also suggest that JAK inhibitors should be tested in a broader range of APS-1 patients.
Pseudohypoparathyroidism and related disorders belong to a group of heterogeneous rare diseases that share an impaired signaling downstream of Gsα-protein-coupled receptors. Affected patients may ...present with various combination of symptoms including resistance to PTH and/or to other hormones, ectopic ossifications, brachydactyly type E, early onset obesity, short stature and cognitive difficulties. Several years ago we proposed a novel nomenclature under the term of inactivating PTH/PTHrP signaling disorders (iPPSD). It is now of utmost importance to validate these criteria and/or improve the basis of this new classification.
Retrospective study of a large international series of 459 probands and 85 relatives molecularly characterized.
Information on major and minor criteria associated with iPPSD and genetic results were retrieved from patient files. We compared the presence of each criteria according to the iPPSD subtype, age and gender of the patients.
More than 98% of the probands met the proposed criteria for iPPSD classification. Noteworthy, most patients (85%) presented a combination of symptoms rather than a single sign suggestive of iPPSD and the overlap among the different genetic forms of iPPSD was confirmed. The clinical and molecular characterization of relatives identified familial history as an additional important criterion predictive of the disease.
The phenotypic analysis of this large cohort confirmed the utility of the major and minor criteria and their combination to diagnose iPPSD. This report shows the importance of having simple and easily recognizable signs to diagnose with confidence these rare disorders and supports a better management of patients.
Background
The underlying mechanisms of obesity in X-linked hypophosphatemia (XLH) are not known. We aimed to evaluate whether FGF21, an endocrine FGF involved in the regulation of carbohydrate–lipid ...metabolism, could be involved.
Methods
We performed a prospective multicenter cross-sectional study comparing FGF23, Klotho, and FGF21 levels in teenagers with XLH compared to healthy controls (VITADOS cohort) after matching for age, gender, and puberty. Non-parametric tests were performed (results presented as median (min–max)).
Results
A total of 40 XLH teenagers (
n
= 20 Standard Of Care, SOC,
n
= 20 burosumab) were included. While patients receiving burosumab displayed increased BMI as compared to patients receiving SOC, systolic blood pressure expressed as percentile was progressively and significantly lower when comparing the three groups: 77 (4–99) in SOC, 47 (9–98) in burosumab, and 28 (1–94) in controls (
p
= 0.007). When compared to patients receiving SOC, patients receiving burosumab displayed significantly increased phosphate and 1,25(OH)2D levels. We found increased Klotho levels in patients receiving burosumab. No differences were found for either carbohydrate–lipid biomarkers or FGF21 between the three groups. A total of 21 XLH patients (53%) had insulin resistance (HOMA > 2.4,
N
= 10 SOC,
N
= 11 burosumab).
Conclusion
FGF21 does not explain obesity/overweight in XLH. Of note, this study was performed in France in 2018–2019, early after the approval authorizing burosumab only in case of severe XLH despite SOC. As such, the data on systolic blood pressure highlighting a possible impact of burosumab to decrease blood pressure as well as increase Klotho levels deserve further studies given their potential effect on long-term cardiovascular risk.
Graphical Abstract
A higher resolution version of the Graphical abstract is available as
Supplementary information
Abstract
Introduction
Vitamin D–dependent rickets type 1A (VDDR1A) is a rare genetic disease associated with loss-of-function variations in the gene encoding the vitamin D–activating enzyme ...1α-hydroxylase (CYP27B1). Phenotype-genotype correlation is unclear. Long-term outcome data are lacking. The objective of this study was to describe characteristics and outcomes to search for a phenotype-genotype correlation.
Methods
We retrospectively collected clinical data, genetic features, and outcomes from 24 genetically confirmed cases from 10 French centers; results are presented as median (min–max).
Results
Clinical symptoms at diagnosis (age, 1.5 0.5-8.7 years) were mainly bone and neurological abnormalities, and laboratory data showed hypocalcemia (1.97 1.40-2.40 mmol/L), hypophosphatemia (−3.4 −13.4 to (−)0.2 SD score for age), low 25OHD and low 1,25(OH)2D3, secondary hyperparathyroidism with PTH at 6.6 (1.3-13.7) times the upper limit for normal (ULN; PTH expressed as ULN to homogenize data presentation), and increased alkaline phosphatase (1968 521-7000 IU/L). Bone radiographs were abnormal in 83% of patients. We identified 17 variations (11 missense, 3 frameshift, 2 truncating, and 1 acceptor splice site variations) in 19 families (homozygous state in 58% 11/19). The partial loss-of-function variation p.(Ala129Thr) was associated with a milder phenotype: older age at diagnosis, higher serum calcium (2.26 vs 1.85 mmol/L), lower PTH (4.7 vs 7.5 ULN), and lower alkaline phosphatase (759 vs 2082 IU/L). Patients were treated with alfacalcidol. Clinical (skeletal, neurological), biochemical, and radiological outcomes were satisfactory, and complications occurred if there was bad adherence.
Conclusion
Overall, our findings highlight good outcomes under substitutive treatment and the need of a closer follow-up of eyes, teeth, kidneys, and blood pressure in VDDR1A.
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