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.

SUMMARY The extent to which low-frequency (minor allele frequency [MAF] between 1–5%) and rare (MAF ≤ 1%) variants contribute to complex traits and disease in the general population is largely unknown. Bone mineral density (BMD) is highly heritable, is a major predictor of osteoporotic fractures and has been previously associated with common genetic variants1–8, and rare, population-specific, coding variants9. Here we identify novel non-coding genetic variants with large effects on BMD (ntotal = 53,236) and fracture (ntotal = 508,253) in individuals of European ancestry from the general population. Associations for BMD were derived from whole-genome sequencing (n=2,882 from UK10K), whole-exome sequencing (n= 3,549), deep imputation of genotyped samples using a combined UK10K/1000Genomes reference panel (n=26,534), and de-novo replication genotyping (n= 20,271). We identified a low-frequency non-coding variant near a novel locus, EN1, with an effect size 4-fold larger than the mean of previously reported common variants for lumbar spine BMD8 (rs11692564[T], MAF = 1.7%, replication effect size = +0.20 standard deviations [SD], Pmeta = 2×10−14), which was also associated with a decreased risk of fracture (OR = 0.85; P = 2×10−11; ncases = 98,742 and ncontrols = 409,511). Using an En1Cre/flox mouse model, we observed that conditional loss of En1 results in low bone mass, likely as a consequence of high bone turn-over. We also identified a novel low-frequency non-coding variant with large effects on BMD near WNT16 (rs148771817[T], MAF = 1.1%, replication effect size = +0.39 SD, Pmeta = 1×10−11). In general, there was an excess of association signals arising from deleterious coding and conserved non-coding variants. These findings provide evidence that low-frequency non-coding variants have large effects on BMD and fracture, thereby providing rationale for whole-genome sequencing and improved imputation reference panels to study the genetic architecture of complex traits and disease in the general population.

Ankylosing spondylitis is a common, highly heritable inflammatory arthritis affecting primarily the spine and pelvis. In addition to HLA-B*27 alleles, 12 loci have previously been identified that are associated with ankylosing spondylitis in populations of European ancestry, and 2 associated loci have been identified in Asians. In this study, we used the Illumina Immunochip microarray to perform a case-control association study involving 10,619 individuals with ankylosing spondylitis (cases) and 15,145 controls. We identified 13 new risk loci and 12 additional ankylosing spondylitis–associated haplotypes at 11 loci. Two ankylosing spondylitis–associated regions have now been identified encoding four aminopeptidases that are involved in peptide processing before major histocompatibility complex (MHC) class I presentation. Protective variants at two of these loci are associated both with reduced aminopeptidase function and with MHC class I cell surface expression.

A genome-wide association study (GWAS) for open angle glaucoma (OAG) blindness was conducted using a discovery cohort of 590 cases with severe visual field loss and 3956 controls. Genome-wide significant associations were identified at TMCO1 (rs4656461 (G) OR=1.68, p=6.1x10 -10 ) and CDKN2B-AS1 (rs4977756 (A) OR = 1.50, p=4.7x10 -9 ). These findings were replicated in a second cohort of advanced OAG cases (rs4656461 p=0.010; rs4977756 p=0.042) and two further cohorts of less severe OAG. The study wide odds ratios are 1.51 (1.35-1.68), p=6.00x10 -14 at TMCO1, and 1.39 (1.28-1.51), p=1.35x10 -14 at CDKN2B-AS1 (also known as CDKN2BAS and ANRIL). Carriers of 1 or more risk alleles at both loci concurrently are at >3-fold increased risk of glaucoma. We demonstrate retinal expression of genes at both loci, and show that CDKN2A and CDKN2B are strongly upregulated in an animal model of glaucoma.Glaucoma is a group of neurodegenerative ocular diseases united by a clinically characteristic optic neuropathy. It is the second leading cause of blindness worldwide 1 . Primary open angle glaucoma (OAG) is the commonest subtype 1 . OAG pathogenesis and factors determining disease progression are poorly understood. Early intervention with measures to reduce intraocular pressure retards visual loss in most individuals 2 , but many cases of glaucoma remain undiagnosed until irreversible vision loss has occurred. Elucidation of SNPs associated with severe outcomes could enable better targeting of treatments which carry cost and morbidity, to individuals at highest risk of blindness. Linkage and candidate gene studies have identified several genes likely to be involved in OAG including myocilin 3 and NTF4 4 , although for the latter, findings have varied in different populations 5 . A recent GWAS using Icelandic OAG cases of unselected severity identified association with variants near CAV1 6 . To identify genes predisposing individuals to OAG blindness, we performed a GWAS in Australian Caucasians with advanced OAG (individuals with OAG who have progressed to severe visual field loss or blindness).