ESPE Abstracts

Background: Giant cell granulomas (GCG) are uncommon bony lesions that most commonly affect the maxilla and mandible; whilst generally benign they can be disfiguring to the face. Historically, GCGs have been treated with steroids or bisphosphonates to try and avoid surgical resection. Over recent years denosumab, a human monoclonal antibody which acts against the receptor activator of nuclear factor kappa B ligand, has been shown to be effective in treating GC...

Introduction: Osteogenesis Imperfecta (OI) is a group of rare hereditary collagen disorders. Vertebral compression fractures and vertebral deformities are well-known complications of OI. Intravenous zoledronic acid is widely used to improve the bone mineral density in children with OI. This study aimed at assessment of the changes in vertebral compression and shape in children who received regular zoledronic acid infusions.Method...

Background: Osteosclerotic metaphyseal dysplasia (OSMD, OMIM 615198) is an extremely rare autosomal recessive disorder, within the family of sclerosing bone dysplasias. It is a distinctive type of osteopetrosis characterised by a unique pattern of osteosclerosis predominantly involving the metaphyseal margins of the long tubular bones. OSMD is characterised by skeletal deformity and multiple fractures and associated clinically with developmental delay, hypoton...

Background: X-linked hypophosphataemic rickets (XLH) is a genetic disorder, characterized by hypophosphatemia and caused by a mutation in the phosphate regulating endopeptidase homolog, X-linked (PHEX) gene which leads to overexpression of fibroblast growth factor 23 (FGF23).1,2 Conventional therapy, supplementation with oral phosphate and vitamin D analogs, does not treat the underlying cause of the disorder and is associated with poor treatment ad...

Introduction: Hypophosphatemic rickets is usually due to genetic causes but in rare cases it can develop secondary to MAS, Fanconi syndrome, or oncogenic causes. Oncogenic osteomalacia, also called Tumor-Induced Osteomalacia (TIO), is a rare acquired paraneoplastic syndrome that develops as a result of excessive phosphate loss from renal tubules by FGF23 released from tumour tissue. In addition to the clinical features of rickets, gait disturbances, growth ret...

Background & Aim: Vitamin D-dependent rickets type 1 A (VDDR1A) is an autosomal recessive condition caused by mutation in CYP27B1, which encodes 1 α-hydroxylase enzyme that catalyzes the conversion of 25-hydroxyvitamin D (25OHD) to 1,25-dihydroxyvitamin D (1,25 (OH)2D). We are reporting 4 cases of VDDR1A due to CYP27B1 mutation initially misdiagnosed as vitamin D deficient and hypophosphatemic rickets.<p class="abstext...

Background: Neonatal severe hyperparathyroidism (NSHPT) is a rare disorder caused by inactivating calcium-sensing receptor (CASR) mutation characterized by striking hyperparathyroidism leading to severe hypercalcemia. Heterozygous loss of function in CASR gives rise to a benign variant called familial hypocalciuric hypercalcemia which needs no treatment. We are reporting 3 cases of NSHPT due to inactivating homozygous CASR mutation n...

Objective: Hereditary hypophosphatemic rickets is a rare renal phosphate wasting disorder causing burden on pediatric patients despite conventional treatment of phosphate and calcitriol. The aim of this study is to analyze genetic and clinical variability of children with X-linked hypophosphatemic rickets (XLHR), focusing on short term, long term and pubertal impact of conventional treatment. Design: Retrospective cohort studyMet...

Vosoritide is a C-type Natriuretic Peptide (CNP) analogue therapy for treatment of achondroplasia. Vosoritide acts on growth plate chondrocytes through the Natriuretic Peptide Receptor-B to stimulate increased endochondral bone growth, leading to increased growth velocity in treated subjects. In Phase II clinical studies, subject blood and urine samples were analyzed to monitor putative bone growth biomarkers including cross-linked C-terminal telopeptides of collagen II (CTxII...

Background: X linked hypophosphatemic rickets (XLHR; OMIM 307800) is an X linked dominant disorder caused by mutations in the phosphate regulating neutral endopeptidase homolog X linked (PHEX) gene, which is located at Xp22.11.Objective: To clarify the underlying mechanism of a Brazilian family with hypophosphatemic rickets whose clinical manifestations were very broad among members of different generations.<p class=...

Background: X-Linked hypophosphatemic rickets (XLH) is a disorder of phosphate homeostasis, characterized by renal phosphate wasting and hypophosphatemia, with normal to low 1,25-dihydroxy vitamin D3 serum levels. PHEX is the gene defective in XLH and different mutations and genomic rearrangements have been described in different families affected by this disease.Objectives: To detect inactivating mutations in the PHEX g...

Introduction: Primary osteoporosis (POP) is a rare and important problem in childhood that can cause serious skeletal deformities and morbidity. In this study, we aimed to reveal the spectrum of POP in childhood, and also to assess the effectiveness and safety of bisphosphonates in increasing BMD, reducing fractures, and improving quality of life.Method: Patients with POP and who received at least one course of pamidrona...

Introduction: X-linked hypophosphatemia (XLH) is a rare hereditary condition caused by mutation in the gene encoding the phosphate-regulating endopeptidase homolog, X-linked (PHEX). It is characterized by altered phosphate homeostasis with persistent hypophosphatemia and hyperphosphaturia resulting in deficient skeletal mineralization, rickets, bone deformity, growth failure, dental problems, joint pain and impairment.Case Prese...

Retinoic acid receptor agonists can have dramatic negative effects on growth and even induce premature growth cessation and epiphyseal fusion (1, 2). An 11 5/12-year-old, prepubertal girl with fibrodysplasia ossificans progressiva presented in our pediatric skeletal disorders clinic with the concern of early growth cessation. She had participated in a clinical trial of Palovarotene (“MOVE”, NCT03312634), a retinoic acid receptor-gamma agonist, since the age of 9 10/1...

Aggrecan is a structural glycoprotein of the extracellular matrix of cartilage present in the articular cartilage, growth plate and cartilage of the intervertebral disc. Biallelic pathogenic variants are the cause of aggrecan type spondyloepiphyseal dysplasia (OMIM#612813) while the presence of heterozygous pathogenic variants determine Kimberley type spondyloepiphyseal dysplasia (OMIM#608361) and short stature associated or not with acceleration of bone maturation and early o...

Background: Signaling through the phosphoinositid-3-kinase (PI3K) pathway modulates bone development and remodeling. We aimed to dissect the role of phosphatase and tensin homolog (Pten), a negative regulator of PI3K signaling, in osteoprogenitor cells.Methods: Femura, tibiae and bone marrow stromal cells (BMSCs) from mice with Cre-inducible Pten knockdown in cells expressing the transcription factor Osterix (Pten cKO) a...

Introduction: Primary hyperparathyroidism (PHPT), often caused by a single adenoma (80%–85%) or hyperplasia or adenomas involving multiple glands, is the major cause of hypercalcemia. PHPT is common and occurs in individuals of all ages, but its prevalence is lower in young adults. Parathyroid tumors and PHPT can be caused by germline (hereditary PHPT) or somatic mutations of tumor suppressor genes (e.g., multiple endocrine neoplasia type 1 and CDC73) and...

Background: Calcium homeostasis is primarily regulated by vitamin D. In the absence of the active hormone or a functional receptor, bones are inadequately mineralized, leading to the development of rickets. Vitamin D-dependent rickets type 2 (VDDR2) is a rare autosomal recessive disorder caused by mutations in the vitamin D receptor (VDR) gene.Case Report: A 12-months-old girl was transported to the local hospital ED with a three-minute ...

Background: Raine syndrome (RS) also known as lethal osteosclerotic bone dysplasia, is a rare autosomal recessive bone disorder. Most of patients with RS die within the first days or weeks of life due to pulmonary hypoplasia. The causative gene FAm20C is located on chromosome 7p22.3. FAm20C is one of the genes that regulate phosphate production. Here, we present a case of RS with hypophosphatemic rickets and a new mutation in FAm2</s...

Background: Tamoxifen is a selective estrogen receptor modulator，administrated in girls with precocious puberty such as McCune-Albright syndrome.Objective: To explore the effect of tamoxifen on the linear growth of precocious pubertal female rats.Method: At 16-22 day of age, 16 precocious pubertal female rats(induced by 300 μg danazol s.c. at 5-day old), were randomized...

Autosomal dominant pseudohypoparathyroidism type-Ib is characterized by renal parathyroid hormone resistance, with resultant hypocalcemia and hyperphosphatemia. This disorder is associated with an isolated loss of methylation at GNAS exon A/B and most patients carry maternal microdeletions in the neighboring STX16 gene. The shortest deletion overlap is a 1.2-kb region spanning STX16 exon 4 and thought to harbor a cis-acting element regulating GNAS A/B methylation. However, abl...

Introduction: Heterozygous inactivating mutations of the calcium-sensing receptor encoding gene (CASR) cause autosomal dominant familial hypocalciuric hypercalcemia (FHH), whereas mutations that inactivate both alleles cause neonatal severe hyperparathyroidism (NSHPT), a rare and potentially fatal disease. We present the clinical and genetic characterization of a Portuguese family with FHH/NSHPT as well as the long-term follow-up of the proband.<p class="a...

Background and Aims: The most effective environmental factor that affect longitudinal growth is nutrition, but the exact composition and the relative benefits of specific dietary proteins in supporting linear growth is unknown. In the current study, we compared the effect of whey and soy proteins on linear growth and bone strength in young fast growing male rats. Both proteins contain all essential amino acids and are considered the best proteins in their cate...

Introduction: Primary osteoporosis are frequently linked to syndromic conditions such as osteogenesis imperfecta which also involves extra esqueletic tissues. With the advancement of medicine, this group has been reduced, due the ability to specifying the causal pathogenic variants. Among these, the LRP5 (Low-density lipoprotein receptor-related protein 5) gene mutations are the most frequent cause. LPR5 is a fundamental coreceptor in the wnt/betacatenin signa...

Introduction: The optimal level of 25-OH-Vitamin D in children is not clear since most studies have been performed on adults. Creating normal levels is problematic since the recommended level of vitamin D is based on the effect of vitamin D on other parameters and not upon its level in the population.Methods: This is a "big-data" study in which we analyzed Vitamin D tests from 49,935 children sampled in Clalit He...

Objective: To recognize Schimke immune-osseous dysplasia from a case of spinal epiphyseal dysplasia.Method: Summarize the characteristics of one case of Schimke immune-ossesous dysplasia, and increase awareness of this disease.Result: The patient, male, with non-consanguineous parents, was born on May 8, 2012. He was hospitalized in our hospital in January 2020 due to his short stature for more tha...

Introduction: Hyperparathyroidism is a disorder usually seen in adults and rarely in childhood.Case: A 14 years and 7 months old girl complaining of constipation applied to pediatric gastroenterology department was consultant to pediatric endocrinology department due to increased plasma calcium levels. She was healthy previously and had no vitamin D usage. In her physical exam; body weight: 53.8kg (-0.12 SD), height: 153,5cm (-1.32 SD), ...

Background: Osteogenesis imperfecta (OI) is a genetic disorder characterized by diffuse osteoporosis, recurrent fractures, and resulting deformities. Bruck syndrome (BS) is a rare autosomal recessive disease that manifests with many symptoms of OI. In addition to the deficiency of type I collagen in OI, congenital joint contractures also occur in BS. BS is caused by mutations of FKBP10 (BS type 1) and PLOD2 (BS type 2) genes encoding the chaperone-collagen com...

Introduction: Vertebral fractures (VFs) are a common and severe finding in secondary and primary osteoporosis. VFs in patients with osteogenesis imperfecta (OI) are an important factor of morbidity and mortality and their presence serves as supportive evidence to initiate bisphosphonate (BP) therapy. In children, VFs have the potential to reshape and regain their original configuration. Vertebral reshaping is regarded a desired effect of BP therapy in children...

Background: Familial Hypocalciuric Hypercalcemia (FHH) type 1 is a benign condition of hypercalcemia with autosomal dominant inheritance caused by pathogenic variants in the calcium-sensing receptor gene (CASR). CaSR plays a crucial role in the regulation of calcium balance. Inactivating mutations in CASR result in altered calcium-sensing and inappropriate parathyroid hormone (PTH) release concerning the calcium concentration. Dysplasia Epiph...

Background: Heterozygous inactivating mutations in the calcium sensing receptor (CaSR) gene cause mild hypercalcemia, normal to slightly elevated parathormone (PTH) levels and may vary from an asymptomatic clinical picture to a mild course. This clinical picture is also called familial hypercalcemic hypocalciuria. In this study, it is aimed to present two sibling cases due to CaSR mutation with interesting features.Case...

Introduction: Parathyroid adenoma (PRAD) is less common than in adulthood, but its morbidity is higher in children. The typical presentation is incidentally discovered as asymptomatic hypercalcemia. We aimed to evaluate the clinical characteristics of PRAD and our clinical experience since the early disease is often asymptomatic.Method: From 2010-2020, all children diagnosed with PRAD at our institution ...

Context: Nutritional vitamin D deficiency is rare in the high income countries; its manifestations are usually associated with the combination of accompanying risk factors, as malnutrition, chronic illness, dark skin or restricted exposure to sunlight due to cultural practices.Objective: The aim of this case report is to increase the awareness to severe vitamin D deficiency as a result of extreme indoor isolation due to ...

Background: X-linked hypophosphatemia (XLH) is a rare, often debilitating genetic disorder caused by mutations in the phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) that is characterized by excess fibroblast growth factor 23 (FGF23), hypophosphatemia, skeletal deformities, and growth impairment.1,2 Conventional therapy with the combination of phosphate and active vitamin D is associated with poor treatment adh...

Introduction: Pseudohypoparathyroidism (PHP) is a group of heterogenous disorders characterized by end organ resistance to parathyroid hormone (PTH) action. In 1942, Fuller Albright first described the phenotype of Albright Hereditary Osteodystrophy (AHO) associated with end organ hormone resistance (brachydactyly, rounded face, short stature, central obesity, subcutaneous ossifications, and variable degrees of mental retardation). Recently EuroPHP network pro...

Introduction: Achondroplasia is the most common of the skeletal dysplasias and short stature with severe anatomic disproportion. Bone endochondrial growth is affected. The entity was described by Depaul in 1851 and the name which comes from the Greek word chondros (cartilage) and plasis (formation) was given by Parrot. It is an autosomal dominant monogenic disease with complete penetrance. Incidence is 1/25000 to 1/40000 of live births. It is caused by a mutat...

Introduction: Familial hypomagnesemia with secondary hypocalcemia is a rare autosomal recessive disease characterized by very low serum magnesium levels. It is caused by mutations in the gene encoding the transient receptor potential melastatin 6 (TRPM6). It typically occurs in the first months of life with symptoms of increased neuromuscular excitability such as convulsions, muscle spasms and tetany. Prolonged untreated hypomagnesemia may lead to developmenta...

Introduction and Aim: FGF-23 is a hormone that works by inhibiting phosphorus reabsorption in kidneys, and systematic regulation of phosphate homeostasis by FGF23 depends on the activity of the membrane protein Klotho. It affects the active vitamin level according to the bioactive free vitamin hypothesis, which binds DVBP to vitamin D and prolongs its half-life. In this study, it was aimed to investigate 1.25 (OH) Vitamin D, Vitamin D Binding Protein, FGF-23 a...

Introduction: Barakat Syndrome (HDR Syndrome) components are hypoparathyroidism (H), sensorineural deafness (D) and renal disease (R) caused by an autosomal dominant inheritance, being mostly associated with deletions in chromosome 10p14 or mutations in GATA3 gene.Case Report: An 11 years old female, was born to non-consanguineous parents. She came to an emergency department complaining of the occurrence of one attack of tonic convulsion...

Introduction: Hereditary causes of rickets often take longer to be diagnosed because they are not very frequent. 1α-hydroxylase alteration is the most frequent vitamin D-dependent rickets. A delay in the treatment associated to a late diagnosis generates an abrupt parathormone deficiency. When initiating treatment, these patients have a risk of hungry bone syndrome.Case: 2-year-8-month-old male patient, with a history of psychomotor...

Background: X-linked hypophosphatemia (XLH) is caused by mutations in PHEX which increases serum Fibroblast Growth Factor 23 (FGF23) concentrations leading to phosphate wasting and osteomalacia. Burosumab is a recombinant fully human IgG1 monoclonal antibody which selectively inhibits the activity of FGF23. In clinical trials burosumab demonstrated significant clinical improvements in radiological rickets severity, growth, and biochemistry among XLH c...