Bone Abstracts

Background: We identified a family with early onset X-linked osteoporosis and fracturesMethods: We performed whole exome sequencing of the X chromosome in three affected members. After discovering a putative pathogenic variant we performed Sanger sequencing of all exons of this gene in other members of this family and in 95 unrelated men suspected of OI type I without COL1A1/2 mutations. We also genotyped a SNP in this gene (minor allele frequency 0.02) ...

Sclerostin is a major negative regulator of osteoblastic activity. Serum sclerostin has a weak positive association with BMD but contradictory results have been described concerning associations with fractures. These contradictions could be explained by the fact that serum sclerostin does not reflect its action in bone. In this study we question whether serum sclerostin is associated with its expression in bone. In addition we aimed to detect associations between sclerostin in...

Objectives: Metabolic bone disease is a frequent complication of end-stage renal disease, characterised by a decreased bone mineral density, which can be measured with dual-energy X-ray absorptiometry. Its validity as a marker for clinical bone disease and increased fracture risk has never been established in adults with pediatric onset of end-stage renal disease (1–3). Adult survivors of pediatric end stage renal disease have very low bone mineral density and small statu...

Background: Puberty is highly important for the accumulation of bone mass. Bone turnover and bone mineral density can be affected in transgender adolescents when puberty is postponed by gonadotropin-releasing hormone analogues (GnRHa), followed by treatment with cross-sex hormone therapy (CSHT).Objective: To investigate the effect of GnRHa and CSHT on bone turnover markers (BTMs) and bone mineral apparent density (BMAD) in transgender adolescents.<p ...

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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...

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...

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...

In XLH, high circulating FGF23 causes hypophosphatemia, rickets, and short stature. In our Phase 2 study, 52 XLH children (ages 5-12 years, ≥Tanner 2) were randomized to receive KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). Serum phosphate (Pi) was measured biweekly. KRN23 dose was titrated (maximum 2 mg/kg) targeting age-appropriate serum Pi concentrations.The first 36 subjects had a mean 6.6 years of standard-of-care treatment before wash...