Bone Abstracts

Background: Severe vitamin D deficiency (VDD), is a common disorder, which has complications including rickets, hypocalcaemia, hypotonia, delayed development and cardiomyopathy. Although nutritional rickets associated craniosynostosis has been reported, there is little awareness of this or knowledge about its clinical course or severity. We present five cases of late onset craniosynostosis in association with nutritional rickets.Clinical presentation: Th...

Short stature and osteoporosis are common in DMD. Disease progression can be slowed by glucocorticoids but these are associated with further growth retardation and skeletal fragility. The defect in growth and skeletal development in children with DMD is probably multifactorial and not solely dependent on glucocorticoid exposure. The muscular dystrophy x-linked (mdx) mouse is the most commonly used animal model of DMD. However, its growth phenotype has not been studied...

Objectives: FGF23 is expressed in clusters of osteocytes at the trabecular periphery suggesting that FGF23-expressing osteocytes are confined to specific basic multicellular units (BMUs) at the trabecular surface. Higher numbers of FGF23-expressing osteocytes are found in chronic kidney disease (CKD) patients with preserved skeletal mineralization indices. We thus combined immunohistochemistry and quantitative backscattered electron imaging (qBEI) to explore the hypothesis tha...

Background: There is significant inter and intraobserver variability in diagnosing vertebral fractures in children. We aimed to evaluate the diagnostic accuracy of morphometric vertebral fracture analysis (MXA) using a 33-point software programme designed for adults, on dual-energy x-ray absorptiometry (DXA) images of children.Methods: Lateral spine DXA images of 420 children aged between 5 and 18 years were retrospectively reviewed. Vertebral fracture a...

Objectives: From late 2015 a new protocol for zoledronic acid was adopted in our centre. This led to many children changing from pamidronate (PAM) to zoledronic acid (ZA) treatment. In a minority of cases the children and/or their families felt strongly that they wanted to change back to PAM. We present the characteristics of that minority and how bone turnover markers (BTMs) and bone mineral densities (BMD) changed whilst on ZA.Method: From Nov 2016 to ...

Fibrous dysplasia (FD) is a benign skeletal disease caused by activating mutations of Gsα. These mutations lead to formation of abnormal and mechanically unsound bone and fibrotic tissue. Clinical sequelae include deformity, fracture, and pain. Studies in bisphosphonates have shown improvement in bone pain and inconsistent effects on FD mineralization; however interpretation has been limited by a lack of controlled trials.Objecti...

Parathyroid hormone (PTH) is used to stimulate bone formation in osteoporotic patients, however concerns have been raised about the quality of the matrix produced since lower levels of total matrix mineral have been reported in osteoporotic and fracture patients treated with PTH. High resolution synchrotron-based Fourier Transform Infrared Microscopy (sFTIRM) was used to determine mineral content in age-matched bone during anabolic PTH treatment, using the simplified lamellar ...

Sclerostin, encoded by the SOST gene, functions as an inhibitor of the Wnt pathway and thus it is an important regulator of bone homeostasis. The fact that osteoblasts, the only cells expressing SOST, lay buried deeply in the bone matrix, poses intrinsic difficulties to the study of the regulation of this gene. Since RUNX2 and SP7/OSX are two known regulators of the differentiation of cells of the osteoblastic lineage, the aim of this study was to determine t...

Introduction: Hypophosphatasia (HPP) characterized by reduced mineralization occurs from mutations in the tissue non-specific alkaline phosphatase (ALPL) gene. Individuals harbouring bi-allelic mutations are generally reported to be severely affected. We report the findings of in vitro functional studies following site-directed mutagenesis in bi-allelic mutations causing extreme clinical phenotypes; severe perinatal and asymptomatic HPP.Objectiv...

Children with 21-hydroxylase deficiency (21-OHD) need chronic glucocorticoid (cGC) therapy to replace congenital deficit of cortisol synthesis, and this therapy is the most frequent and severe form of drug-induced osteoporosis. In the study we enrolled 18 patients (9 females) and 18 sex- and age-matched controls. We found in 21-OHD patients high serum and leukocyte levels of dickkopf-1 (DKK1), a secreted antagonist of the Wnt/β-catenin signaling pathway, known to be a key...