Bone Abstracts

Background: Idiopathic infantile hypercalcemia (IIH) is a rare disorder caused by CYP24A1 loss-of-function mutation, resulting in impaired degradation of 1,25-dihydroxyvitamin D3. Typical signs include muscle hypotonia, dehydration, failure to thrive, psychomotor retardation, constipation, nephrocalcinosis. IIH should be distinguished from other causes of hypercalcemia in infancy. Treatment includes low calcium diet, glucocorticoids, furosemide, calcitonin. Pamidron...

Introduction: Heterotopic ossification (OH) is a rare condition characterized by the presence of extra-skeletal ossification; in most cases OH is due to the inactivation of the gene of guanine nucleotide-binding protein alpha-stimulating activity polypeptide (GNAS). In some cases they remain confined to skin and subcutaneus tissues (osteoma cutis, Albright hereditary osteodystrophy (AHO), pseudohypoparathyroidism type 1a and c (PHP1a/c), and pseudopseudohypothyroidism (PPHP)),...

Objectives: Special dual-energy X-ray absorptiometry (DXA) protocols permit quantification of bone mineralization, fat mass, and fat distribution in infants. Our objective was to evaluate the accuracy and precision of a multiscan acquisition protocol designed to allow for reflection and imputation analysis for regions with movement.Methods: The IMPAACT P1084s Study assesses bone and kidney safety of antiretrovirals used for PMTCT. Newborns received a spi...

Osteogenesis imperfecta is a clinically heterogeneous heritable connective tissue disorder. Most OI cases are due to mutations in type I collagen genes, COL1A1 and COL1A2 encoding the pro-alpha1(I) and pro-alpha2(I) chains respectively. However, genotype–phenotype correlation has not been completely elucidated yet. In this study we evaluated a familial case including a mother and a daughter, classified as OI type I. The daughter had more severe clinical ...

In recent years, the important role in bone remodelling Wnt/β-catenin pathway is highlighted. Key receptor of this pathway is LDL receptor-related protein 5 (LRP5). It was demonstrated in adults that polymorphism in LRP5 gene was associated with bone mineral density and fracture risk. So far no such studies were conducted in children.The aim of the study was the analysis of LRP5 and COL1A1 genes in a patient with r...

Aim: Scoliosis is a common skeletal problem affecting 10–30% of patients with neurofibromatosis type 1 (NF1). NF1 patients have been shown to have reduced bone mineral density (BMD) which may play a role in the pathogenesis or progression of scoliosis. Our centre is one of four international centres currently evaluating the efficacy of various spinal imaging techniques and BMD as predictors for scoliosis in NF1. In our cohort we measured the lumbar spine (LS) BMD both by ...

The purpose of this presentation is to present the guidelines for recommending surgery for asymptomatic primary hyperparathyroidism, based on a workshop held in 2013. The indications for surgery were: i) a serum calcium more than 1 mg/dl (or 0.25 mmol/l) above the reference interval; ii) a low bone density (T-score −2.5 or less at the lumbar spine, total hip, femoral neck, or distal radius 1/3) or presence of vertebral fracture; iii) chronic kidney disease stage...

Background: Cannabinoid receptors are expressed in synovial joints but their role in joint disease is unknown. Here we examined the role of the type 2 cannabinoid receptor (CB2) in the pathogenesis of age-related osteoarthritis and osteoarthritis caused by destabilisation of the medial meniscus (DMM) in WT and CB2-deficient mice (Cnr2−/− mice).Methods: The severity of arthritis was graded histologically according to standard techni...

Hip+ fracture rate in Norway is the highest registered in World, and more than double that of Spanish women. Previous studies were unable to demonstrate significant differences between the two populations with respect to bone mass or calcium metabolism. In order to test, whether the difference in fracture propensity between both populations could be explained by differences in bone material quality we assessed bone material strength using microindentation in 41 Norwegian and 4...

Background: LRP4 gene encodes a member of the LDL receptor gene family, expressed by osteoblasts, which negatively regulates Wnt/β-catenin signalling by potentiating the inhibitory effect of sclerostin on LRP5 signalling. Previously, missense mutations of LRP4 have been described in patients with the phenotype of sclerosteosis, a disease associated with high bone mass and bone overgrowth. Here we investigated the hypothesis the LRP4 mut...