Bone mineral density (BMD) is the most important predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and East Asian ancestry. We tested the top-associated BMD markers for replication in 50,933 independent subjects and for risk of low-trauma fracture in 31,016 cases and 102,444 controls. We identified 56 loci (32 novel)associated with BMD atgenome-wide significant level (P<5×10−8). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal-stem-cell differentiation, endochondral ossification and the Wnt signalling pathways. However, we also discovered loci containing genes not known to play a role in bone biology. Fourteen BMD loci were also associated with fracture risk (P<5×10−4, Bonferroni corrected), of which six reached P<5×10−8 including: 18p11.21 (C18orf19), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility.

Background-Vitamin D is crucial for maintaining musculoskeletal health. Recently, vitamin D insufficiency has been linked to a number of extraskeletal disorders, including diabetes, cancer, and cardiovascular disease. Determinants of circulating 25-hydroxyvitamin D (25-OH D) include sun exposure and dietary intake, but its high heritability suggests that genetic determinants may also play a role.

To identify novel genetic risk factors for rheumatoid arthritis (RA), we conducted a genome-wide association study (GWAS) meta-analysis of 5,539 autoantibody positive RA cases and 20,169 controls of European descent, followed by replication in an independent set of 6,768 RA cases and 8,806 controls. Of 34 SNPs selected for replication, 7 novel RA risk alleles were identified at genome-wide significance (P<5×10−8) in analysis of all 41,282 samples. The associated SNPs are near genes of known immune function, including IL6ST, SPRED2, RBPJ, CCR6, IRF5, and PXK. We also refined the risk alleles at two established RA risk loci (IL2RA and CCL21) and confirmed the association at AFF3. These new associations bring the total number of confirmed RA risk loci to 31 among individuals of European ancestry. An additional 11 SNPs replicated at P<0.05, many of which are validated autoimmune risk alleles, suggesting that most represent bona fide RA risk alleles.

IntroductionIn 2008, the UK National Osteoporosis Guideline Group (NOGG) produced a guideline on the prevention and treatment of osteoporosis, with an update in 2013. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women and men age 50 years or over.MethodsWhere available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence.ResultsReview of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment, lifestyle measures and pharmacological interventions, duration and monitoring of bisphosphonate therapy, glucocorticoid-induced osteoporosis, osteoporosis in men, postfracture care and intervention thresholds.ConclusionThe guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals who are involved in its management.

Osteoporosis is a common disease with a strong genetic component, characterized by reduced bone mass and increased fracture risk. Current evidence suggests that the inheritance of bone mass is under polygenic control but the genes responsible are poorly defined. Type I collagen is the major protein of bone encoded by the COLIA1 and COLIA2 genes. While these are strong candidates for the genetic regulation of bone mass, no abnormality of either gene has so far been defined in osteoporosis. In this study, we describe a novel G-->T polymorphism in a regulatory region of COLIA1 at a recognition site for the transcription factor Sp1(7) that is significantly related to bone mass and osteoporotic fracture. G/T heterozygotes at the polymorphic Sp1 site (Ss) had significantly lower bone mineral density (BMD) than G/G homozygotes (SS) in two populations of British women and BMD was lower still in T/T homozygotes (ss). The unfavourable Ss and ss genotypes were over-represented in patients with severe osteoporosis and vertebral fractures (54%), as compared with controls (27%), equivalent to a relative risk of 2.97 (95% confidence interval 1.63-9.56) for vertebral fracture in individuals who carry the 's' allele. While the mechanisms that underlie this association remain to be defined, the COLIA1 Sp1 polymorphism appears to be an important marker for low bone mass and vertebral fracture, raising the possibility that genotyping at this site may be of value in identifying women who are at risk of osteoporosis.