Bone Abstracts

Background: Mutations in the PLS3 gene, encoding plastin 3, cause X-linked osteoporosis. Osteoporosis is characterized by low bone mineral density (BMD) and increased susceptibility to fractures. Here we describe a 7-year-old boy with osteoporosis due to a novel PLS3 deletion.Presenting problem: The patient, born to non-consanguineous parents, had a history of one low-energy long-bone fracture, three vertebral fractures (T5, T6 T8) and kyphosis. DXA scan...

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 ...

Background: Primary tumoral calcinosis is an orphan disease. The data about the incidence of this disease, as well as clinical recommendations for treatment are not presented in the literature.Presenting problem: Two patients – 11.5 years old boy and 8 years old girl with primary tumoral calcinosis had multiple foci of the subcutaneous calcification, walking impossibility, wheel-chair condition, fatigue, high fever and equinus deformity of the left ...

The role of the WNT pathway in skeletal maintenance has been extensively studied since the identification of mutations in key signaling WNT mediators (LRP5 and sclerostin) in high and low bone mass phenotypes. However, the identity of the key WNT ligand that signals via LRP5/6 has remained unknown. We aimed to identify genes with a major effect on the skeleton by studying individuals and families with early-onset osteoporosis or osteogenesis imperfecta (OI).<p class="abste...

Objectives: X-linked hypophosphataemia (XLH) is a rare inherited form of osteomalacia characterised by low blood phosphate levels which lead to inadequate mineralisation of bone and rickets. Burosumab is an anti-FGF23 fully human monoclonal-antibody, and the first treatment to target the underlying pathophysiology of XLH. Real-world evidence is important in validating the findings of clinical studies. We report relevant real-world biochemical data on children under five years ...

Objectives: X-linked hypophosphataemia (XLH) is a rare inherited form of osteomalacia characterised by low blood phosphate levels which lead to inadequate mineralisation of bone resulting in rickets, skeletal abnormalities, physical impairment, weakness, and pain. Burosumab is an anti-FGF23 fully human monoclonal-antibody, and the first treatment to target the underlying pathophysiology of XLH. Real-world evidence is important in validating the findings of clinical studies. We...

The relationship between BMD T-score and FX risk has not been established in patients receiving osteoporosis therapy. In the FREEDOM Extension study, continuous DMAb therapy for up to 10 years increased BMD levels with no therapeutic plateau at lumbar spine or TH [Bone et al, ASBMR 2015]. Such improvements would only be meaningful if associated with FX reductions. We investigated the relationship between TH BMD T-score and NVFX in women who received DMAb during FREEDOM and tho...

Bone has recently emerged as a novel endocrine organ regulating glucose metabolism. Ectonucleotide pyrophosphatase/phosphodiesterase-1 (NPP1) controls bone mineralisation by generating the mineralisation inhibitor pyrophosphate. In clinical studies increased activity of NPP1 has been found in patients with insulin resistance, and it has been shown to directly inhibit the insulin receptor. We hypothesised that mice lacking NPP1 (Enpp1−/−) would exhibit im...

Osteosarcoma is the most frequent primary bone tumor that develops mainly in young adults. The survival rate at 5 years is below 30% for patients with poor response to treatment or with metastasis.The histones modifications are of critical importance in maintaining the transcription program of both normal and tumor cells. The bromodomain and extra-terminal domain (BET) protein family is an important class of ‘histone reading protein’ capable to...

Bone sialoprotein regulates osteoblast activity and bone formation. In knockout (BSP−/−) mouse bone marrow (BM) stromal cell cultures, the pool of osteoprogenitor (OP) cells (CFU-F number) is not different from wild-type (+/+), nor is their early differentiation (same numbers of alkaline phosphatase positive colonies=CFU-ALP, although these are smaller), while the number of osteoblast, mineralized colonies (CFU-OB) is dramatically reduced. Because ossifi...