Bone Abstracts

Background: Bone marrow (BM) adiposity is inversely related to bone mineral density and increases with ageing and menopause. We previously observed that the variation in BM fat fraction was more pronounced in premenopausal women compared to men and postmenopausal women. We hypothesized that the variation in BM fat fraction in premenopausal women is associated with hormonal variations during the menstrual cycle.Objective: To investigate the dynamic change...

Dysosteosclerosis (DSS) is the rare osteopetrosis (OPT) distinguished by metaphyseal osteosclerosis with relative radiolucency of widened diaphyses and platyspondyly. In 2012, mutations in the SLC29A3 gene were discovered to cause DSS.Here, we report a new case of DSS presenting with severe anemia and having a unique homozygous mutation in SLC29A3.Our patient was the 3rd child of consanguineous Turkish parents. She present...

Background: Systemic alterations in Runx2 expression have been shown to affect flat and long bone formation differently: Inactivating mutations cause low-turnover bone disease and patent fontanels in cleidocranial dysplasia, while overexpressing mutations cause metaphyseal dysplasia with maxillary hypoplasia and brachydactyly. The two conditions have inverse skeletal phenotypes. We know of no descriptions of these disorders in a patient without duplications or mutations of Run...

Objectives: In XLH, FGF23-mediated hypophosphatemia leads to defective bone mineralization and rickets. Investigational product KRN23 binds FGF23 and inhibits its activity. The objective of this Phase 2 study was to evaluate the safety and efficacy of KRN23 in 52 children with XLH (ages 5–12 years, ≤Tanner 2).Methods: Patients were randomized to receive KRN23 biweekly (Q2W) or monthly (Q4W) by SC injection. KRN23 dose was titrated (maximum 2 m...

Objectives: In XLH, musculoskeletal outcomes of current treatment with oral phosphate (Pi)/active vitamin D are suboptimal for many patients. In a Phase 2, open-label study, we tested the hypothesis that KRN23 improves rickets and functional outcomes in XLH children.Methods: Fifty-two children with XLH (ages 5–12 years at baseline) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). At study entry, most participants had received oral Pi/a...

Introduction: Perthes disease (PD), idiopathic femoral head avascular necrosis, often results in deformity. The underlying cause is unclear and long-term function is directly related to the roundness of femoral head. Current treatment include mechanical treatments and various surgical procedures, which are therapeutic but can’t prevent collapse. A multicentre, prospective, randomised controlled trial of 12 months zoledronic acid (ZA) in children with PD was conducted. We ...

Objective: We evaluated the long-term efficacy of burosumab, a monoclonal antibody against FGF23, in a Phase 2 Study (NCT02163577) in children with XLH.Methods: Fifty-two children with XLH (5-12 years-old, Tanner ≤ 2) were randomized 1:1 to receive subcutaneous burosumab Q2W or Q4W for 64 weeks. Doses were titrated up to 2 mg/kg/dose targeting serum phosphorus levels within 1.1–1.6 mmol/l. All subjects entered the long-term extension at Week 6...

Objectives: Asfotase alfa (AA), an enzyme replacement therapy, is the only approved treatment for pediatric-onset hypophosphatasia (HPP). We evaluated the safety profile of AA from the clinical trial program spanning pediatric and adult patients.Methods: Safety data were pooled from 4 open-label, multicenter studies in children aged ≤3 years (study 002/003 [NCT00744042/NCT01205152]; n=11) and ≤5 years (study 010-10 [NCT01176266]; <em...

Objectives: X-linked hypophosphatemia (XLH) is a rare genetic disorder of phosphate metabolism caused by mutations in the PHEX gene. This pilot study aims to apply novel imaging techniques to asses the musculoskeletal phenotype of XLH patients by bidirectional axial transmission (BDAT) ultrasound, magnetic resonance spectroscopy (MRS) and high resolution peripheral quantitative computed tomography (HR-pQCT).Methods: BDAT bone ultrasound of the radius and...

Objectives: Glucagon-like peptide 1 is secreted by intestinal L-cells into the blood supply in response to nutrients in the intestine. Although osteoblasts express the GLP-1 receptor (GLP-1R), the main action of the GLP-1/GLP-1R pathway in bone physiology and bone quality is unknown. The aim of the present study was to investigate bone strength and quality in a mouse model of GLP-1R deficiency.Materials/methods: Eight 16 weeks-old GLP-1R knock-out male m...