Bone Abstracts

Background and methods: Pigment epithelium-derived factor (PEDF) is a potent antiangiogenic factor, ubiquitously expressed and secreted in human tissues. Hypertrophic cartilage and osteoblasts express PEDF that binds to type I collagen and glycosaminoglycans in the extracellular matrix. Two rare forms of osteogenesis imperfecta (OI) with intact collagen synthesis are associated with PEDF deficiency. Histological observations revealed excessive osteoid formation and prolonged m...

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...

see P21....

Background: Vitamin D plays an important role in calcium and phosphate homeostasis. Circulating 25 hydroxyvitamin D [25(OH)D] is metabolised into its biologically active form 1,25-dihydroxyvitamin D [1,25-d(OH)D] by the actions of 1α hydroxylase, and into inactive 2metabolite 24,25-dihydroxyvitamin D [24,25-d(OH)D] by 24-hydroxylase. Recent studies suggest the production of 1,25-d(OH)D) from 25(OH)D is 24,25-d(OH)D dependent. Genetic mutations of CYP24A1 gene resulting in...

Background: The relation between sex hormone-binding globulin (SHBG) and vertebral fracture (VFx) is unclear.Aim: To examine whether SHBG is associated with bone mineral density at lumbar spine (LS-BMD), trabecular bone score (TBS) and prevalent VFx.Methods: Data of 6224 men and women participants in the third visit of the first cohort (I-3) and the first visit of the second cohort (II-1) of a prospective population based cohort, w...

Background: Fracture risk is increased in Type 2 diabetes (T2D) individuals. Bone mineral density (BMD) is inversely associated with fracture risk but paradoxically high in T2D individuals. Trabecular bone score (TBS) reflects bone microarchitecture and predicts fracture risk.Objective: We aimed to compare mean lumbar spine TBS (LS-TBS) and lumbar spine BMD (LS-BMD) values, across individuals with and without i) vertebral fracture (VFx), ii) T2D; and iii...

Background: The development of hypophosphataemic rickets in infants fed with the elemental formula (EF) Neocate® has been recently reported. We present seven cases of exclusively Neocate-fed babies who developed hypophosphataemic rickets.Presenting problem: Three patients (P1,3,4) had incidental findings of rickets on chest X-rays, two (P2,6) developed leg deformities and rickets was confirmed on X-rays, and two (P5,6) presented with femu...

Heritability of bone mineral density (BMD) varies at skeletal sites, possibly reflecting different relative contributions of environmental and genetic influences. To quantify shared genetic influences across different sites, we estimated the genetic correlation of BMD at the upper limb (UL), lower limb (LL) and skull (S) obtained from whole body DXA scans, using bivariate genome-wide complex trait analysis (GCTA). The study (n=9395) combined data from the Avon Longitu...

Low levels of 25-hydroxyvitamin D have been documented among inhabitants of the wider Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D. In this study we aimed to determine the optimum time for sun exposure in the Central region of Riyadh, Saudi Arabia. Ampoules containing 7-dehydrocholesterol in ethanol were exposed to sunlight every hour starting from sunrise until sunset in July and December. Our results demonstrated...

see PP282....