Association of osteoporosis susceptibility genes with bone mineral density and bone metabolism related markers in Koreans: the Chungju Metabolic Disease Cohort (CMC) study

Integrative analysis of genetic and clinical risk factors for bone loss in a Korean population

PURPOSE

The relative contribution of genetic and clinical factors for bone loss is not well known. This study aimed to investigate the annualized percentage change in total hip bone mineral density (BMD) and the genetic and clinical risk factors for bone loss in a Korean prospective cohort study over a 6-year period.

METHODS

We included 645 men aged ≥50 years and 683 postmenopausal women who had repeated BMD testing between 2007 and 2014. The association between covariates and annualized percentage change in hip BMD was analyzed through the multivariate linear regression analysis. A total of 2614 single-nucleotide polymorphisms (SNPs) from 23 known BMD-related candidate genes and genome-wise association study were investigated.

RESULTS

Hip bone loss increased more rapidly in women than in men with advancing age. Hip bone loss in men increased with lean mass (LM) loss (%/year) (P < 0.001) and current smoking (P = 0.024) and decreased with increasing waist circumference (WC) (P < 0.001), alcohol consumption (P = 0.049), and increase in red blood cell counts (P = 0.031). Decreasing WC (P = 0.009), LM loss (%/year) (P < 0.001), and years since menopause ≤ 3 years (P = 0.003) significantly correlated with hip bone loss in women aged 45-59 years. Hip bone loss in women aged ≥60 years increased with advancing age (P = 0.012), alcohol consumption (P = 0.028), LM loss (%/year) (P = 0.031), and fat mass loss (%/year) (P < 0.001) and decreased with increasing WC (P = 0.025). LRP5 rs498830 (β = 0.127, P = 0.007) and TNFSF11 rs7325635 (β = 0.146, P = 0.001) were the top SNPs related to hip bone loss in men and postmenopausal women, respectively. However, none of the SNPs were associated with hip bone loss after Benjamini-Hochberg adjustment.

CONCLUSION

In this study, decreasing WC and LM were significant risk factors for hip bone loss in both men and women. Those factors were also identified that had sex-specific or age-specific effects on hip bone loss. None of the SNPs were associated with hip bone loss after multiple testing adjustments. The understanding of the modifiable factors contributing to bone loss has been broadened, and this may have implications such as in developing individualized preventive strategy. Further studies are needed to better predict the risk for bone loss in men and women.

Association between osteoporosis and menopause in relation to SOX6 rs297325 variant in Taiwanese women

OBJECTIVE

Osteoporosis, the most prevalent bone disorder in humans, is a global public health issue and its relationship with menopause is well-established. The interaction between menopause and genes on osteoporosis risk is, however, yet to be fully elucidated. We assessed the association between menopause and osteoporosis in relation to the SOX6 rs297325 variant in Taiwanese women.

METHODS

There were 7,581 female participants, aged 30 to 70 years old. Information on SOX6 rs297325 and menopause were obtained from the Taiwan Biobank Database while that on osteoporosis was obtained from the National Health Insurance Research Database.

RESULTS

Menopause but not SOX6 rs297325 was significantly associated with a higher risk of osteoporosis (odds ratio [OR] = 1.48; 95% confidence interval [CI] = 1.04-2.10). The interaction between menopause and rs297325 on osteoporosis was significant (P = 0.0216). After stratification by rs297325 genotypes, the risk of osteoporosis was significantly higher in menopausal women having the TT + CC genotype (OR = 2.02; 95% CI = 1.21-3.38). After stratification by menopausal status and rs297325 genotypes, the OR; 95% CI was 0.62; 0.38 to 0.99 in premenopausal women with the TC + CC genotype and 1.24; 0.82 to 1.88 in menopausal women with the TC + CC genotype.

CONCLUSION

SOX6 rs297325 was not significantly associated with osteoporosis but might have modulated the association between menopause and osteoporosis. The risk of osteoporosis was higher in menopausal women with the TC + CC genotype but lower in premenopausal women with the TC + CC genotype.

LncRNA ZBTB40-IT1 modulated by osteoporosis GWAS risk SNPs suppresses osteogenesis

Previous genome-wide linkage and association studies have identified an osteoporosis-associated locus at 1p36 that harbors SNPs rs34920465 and rs6426749. The 1p36 locus also comprises the WNT4 gene with known role in bone metabolism and functionally unknown ZBTB40/lncRNA ZBTB40-IT1 genes. How these might interact to contribute to osteoporosis susceptibility is not known. In this study, we show that lncRNA ZBTB40-IT1 is able to suppress osteogenesis and promote osteoclastogenesis by regulating the expression of WNT4, RUNX2, OSX, ALP, COL1A1, OPG and RANKL in U-2OS and hFOB1.19 cell lines, whereas ZBTB40 plays an opposite role in bone metabolism. Treatment with parathyroid hormone significantly downregulates the expression of ZBTB40-IT1 in U-2OS cell lines. ZBTB40 can suppress ZBTB40-IT1 expression but has no response to parathyroid hormone treatment. Dual-luciferase assay and biotin pull-down assay demonstrate that osteoporosis GWAS lead SNPs rs34920465-G and rs6426749-C alleles can respectively bind transcription factors JUN::FOS and CREB1, and upregulate ZBTB40 and ZBTB40-IT1 expression. Our study discovers the critical role of ZBTB40 and lncRNA ZBTB40-IT1 in bone metabolism, and provides a mechanistic basis for osteoporosis GWAS lead SNPs rs34920465 and rs6426749.

SOX6 rs7117858 polymorphism is associated with osteoporosis and obesity-related phenotypes

BACKGROUND

SOX6 has been recently proposed as a pleiotropic gene for obesity and osteoporosis. The aim of this study was to investigate whether the rs7117858 genetic variant in SOX6 was associated with bone mass assessed by quantitative ultrasound (QUS) and obesity-related measures in a population of young adults.

METHODS

A cross-sectional study was conducted in 550 unrelated healthy individuals of Caucasian ancestry (381 (69.3%) female and 169 (30.7%) male; mean age 20.46 ± 2.69). Bone mass was assessed through calcaneal QUS) parameter (BUA, dB/MHz). Obesity-related traits including weight, body mass index (BMI), fat mass (FM) and fat-free mass (FFM) were analysed.

RESULTS

The linear regression analysis revealed that the rs7117858 SNP was significantly associated with FFM after adjustments for covariables in the whole sample (P = 0.027, β (95% CI) = 0.053 (0.092, 1.516). In addition, a significant association with QUS measurement adjusted for confounding factors was found in females (P = 0.043, β (95% CI) = 0.104 (0.138. 8.384).

CONCLUSIONS

We demonstrate for the first time that SOX6 influence FFM and QUS trait in a population of young adults, suggesting the implication of this gene in obesity and osteoporosis-related phenotypes during early adulthood.

VDR and TNFSF11 polymorphisms are associated with osteoporosis in Thai patients

Determining molecular markers for osteoporosis may be valuable for improving the quality of life of affected elderly patients by aiding in early detection and disease management. In the present study, the association between single nucleotide polymorphisms (SNPs) of the vitamin D receptor (VDR) and tumour necrosis factor superfamily number 11 (TNFSF11) genes and the susceptibility of developing osteoporosis was investigated in a Thai female cohort. The study group consisted of 105 Thai postmenopausal patients diagnosed with osteoporosis and 132 healthy Thai postmenopausal female volunteers. DNA extracted from blood samples was used to genotype the VDR and TNFSF11 genes using polymerase chain reaction-restriction fragment length polymorphism and sequencing analysis. For VDR, the frequencies of the genotypes TT, CT and CC for the TaqI SNP (rs731236) were 87.88, 11.36 and 0.76%, respectively, in the control group, while in the osteoporosis cohort were 92.38, 5.71 and 1.91%, respectively. For the FokI SNP (rs2228570), the frequencies of the genotypes CC, CT and TT were 31.06, 55.30 and 13.64%, respectively, in the control group, and in the osteoporosis group were 29.52, 43.81 and 26.67%, respectively. For BsmI SNP (rs1544410), the frequencies of the genotypes GG, GA and AA were 78.03, 18.94 and 3.03%, respectively, in control group, and in the osteoporosis group were 80.95, 18.10 and 0.95%, respectively. The significant risk of osteoporosis associated with the FokI SNP was determined. The odds ratio (95% confidence interval) was 2.30 (1.14-4.69; P=0.01) among patients with osteoporosis with TT as the susceptibility genotype. For TNFSF11, the frequencies of the genotypes TT, CT and CC for the -290C>T SNP (rs9525641) in the control group were 36.36, 50.76 and 12.88%, respectively, while in the osteoporosis group were 31.43, 56.19 and 12.38%, respectively. For the -643C>T SNP (rs9533156), the frequencies of the genotypes TT, CT and CC in the control group were 35.61, 48.48 and 15.91%, respectively, while in the osteoporosis group were 32.38, 55.24 and 12.38%, respectively. For the -693G>C SNP (rs9533155), the frequencies of the genotypes CC, CG, and GG in the control group were 39.39, 46.97 and 13.64%, respectively, and in the osteoporosis group were 36.19, 53.33 and 10.48%, respectively. No significant associations of the TNFSF11 SNPs with osteoporosis were determined; however, it was notable that the GCT haplotype of TNFSF11 may be a protective haplotype for osteoporosis. Therefore, it was concluded that the SNP FokI of VDR may be a potential molecular biomarker for the development of osteoporosis in Thai females.

JAG1, MEF2C and BDNF polymorphisms associated with bone mineral density in women from Northern México

Introduction: Osteoporosis is characterized by a low bone mineral density. Genetic composition is one of the most influential factors in determining bone mineral density (BMD). There are few studies on genes associated with BMD in the Mexican population. Objective: To investigate the association of eight single nucleotide polymorphisms (SNP) of JAG1, MEF2C and BDNF genes with BMD in women of Northern México. Materials and methods: This study involved 124 unrelated Mexican women between 40 and 80 years old. BMD was determined by dual X-ray absorptiometry. Genotyping was performed using allelic discrimination by real time PCR. We analyzed the SNP of JAG1 (rs6514116, rs2273061, rs2235811 and rs6040061), MEF2C (rs1366594, rs12521522 and rs11951031), and BDNF (rs6265) and the data using linear regression. Results: The JAG1 SNP rs2235811 was associated with the BMD of the total body under the dominant inheritance model (p=0,024). Although the other SNPs were not associated with BMD in any of the inheritance models studied, a trend was observed. Conclusion: Our results suggest that the SNP rs2235811 in the JAG1 gene might contribute to the variation in BMD in women from northern México.

AKAP11 gene polymorphism is associated with bone mass measured by quantitative ultrasound in young adults

Background: Due to the increased prevalence of osteoporosis and direct health care cost of osteoporosis-related fractures, there is a growing interest in identifying genetic markers associated with osteoporosis phenotypes in order to develop genetic screening strategies. We aimed to analyze the possible associations between calcaneal Quantitative ultrasound (QUS), a valuable screening tool for assessing bone status in clinical practice, and ZBTB40 (rs7524102, rs6426749), SP7 (rs2016266) and AKAP11 (rs9533090) genes. Methods: A cross-sectional study was conducted on 550 healthy individuals of Caucasian ancestry (381 females and 169 males, median age 20.46±2,69). Bone mass was assessed through QUS to determine broadband ultrasound attenuation (BUA, dB/MHz). Single-nucleotide polymorphisms (SNPs) in ZBTB40 (rs7524102, rs6426749), SP7 (rs2016266) and AKAP11 (rs9533090) were selected as genetic markers and genotyped using TaqMan OpenArray® technology. Results: Linear regression analysis revealed that rs7524102 and rs6426749 in ZBTB40, and rs9533090 in AKAP11 were significantly associated with the calcaneal QUS parameter after adjustments for age, sex, weight, height, physical activity, and calcium intake (p=0.038, p=0.012 and p=0.008, respectively). After applying the Bonferroni correction for multiple testing (p=0.012), only the association of rs9533090 in AKAP11 remained significant. Conclusion:AKAP11 gene (rs9533090) influences QUS trait in a population of Caucasian young adults. The rs9533090 SNP may be considered a factor affecting peak bone mass acquisition.

RANKL/RANK/OPG Polymorphisms and Heel Quantitative Ultrasound in Young Adults

BACKGROUND

The receptor activator of the nuclear factor-kappa B ligand (RANKL), the receptor activator of nuclear factor-kappa B (RANK), and the osteoprotegerin (OPG) signaling pathway play an important role in the regulation of bone remodeling and osteoclast differentiation. Quantitative ultrasound (QUS) is a relatively recent and noninvasive method providing structural information on microstructure, bone elasticity, and connectivity. However, in contrast to bone mineral density measurements, the possible association of the RANKL/RANK/OPG pathway with heel QUS has not been analyzed.

OBJECTIVES

The aim of this study was to assess, for the first time, the contribution of the RANKL/RANK/OPG pathway genes in the genetic background of heel QUS parameters.

METHODS

Ten single-nucleotide polymorphisms (SNPs) of RANKL (rs9594759, rs12585014, rs7988338, rs2148073), RANK (rs1805034, rs12458117, rs3018362), and OPG (rs4355801, rs3102735, rs2073618) were selected as genetic markers and genotyped using Open Array technology in 575 self-reported Caucasian individuals aged 18-25. Bone mass in the right calcaneus was estimated with QUS to obtain the broadband ultrasound attenuation (BUA) measurement (dB/MHz). Linear regression analyses were performed to test the possible association between the SNPs and BUA.

RESULTS

Linear regression analysis of all the tested SNPs revealed no significant association with the BUA parameter after adjusting for age, gender, weight, height, physical activity, and calcium intake. The lowest p-value was observed for the rs9594759 RANKL polymorphism and heel QUS (p = .06; b* = -.075, 95% CI [-0.960, 0.028]).

CONCLUSION

Our results suggest that the polymorphism of the RANKL, RANK, and OPG genes does not make a significant genetic contribution to heel ultrasound measurements in a population of young Caucasian adults. Further studies replicating the results in independent populations are needed to support these initial findings.

The influence of genetic susceptibility and calcium plus vitamin D supplementation on fracture risk

Background: Fracture is a complex trait, affected by both genetic and environmental factors. A meta-analysis of genome-wide association studies (GWASs) identified multiple bone mineral density (BMD) and fracture-associated loci.Objective: We conducted a study to evaluate whether fracture genetic risk score (Fx-GRS) and bone mineral density genetic risk score (BMD-GRS) modify the association between the intake of calcium with vitamin D (CaD) and fracture risk.Design: Data from 5823 white postmenopausal women from the Women's Health Initiative CaD randomized trial were included. Participants received 1000 mg elemental Ca with 400 IU vitamin D3/d or placebo (median follow-up: 6.5 y). Total fracture was defined as first fracture of any type. We computed the Fx-GRS with 16 fracture- and BMD-associated variants, and the BMD-GRS with 50 BMD-associated variants. We used Cox regression and a case-only approach to test for multiplicative interaction. Additive interaction was assessed with the relative excess risk due to interaction (RERI). We analyzed genetic risk score as a continuous variable and a categorical variable based on quartile (quartile 1, quartiles 2-3, and quartile 4).Results: We observed no interaction between the Fx-GRS and CaD on fracture risk; however, we observed a significant multiplicative interaction between the BMD-GRS and CaD assignment (P-interaction = 0.01). In addition, there was a significant negative additive interaction between placebo assignment and higher BMD-GRS: quartiles 2-3, PRERI = 0.03; quartile 4, PRERI = 0.03. In a stratified analysis, the protective effect of CaD on fracture risk was observed in women in the lowest BMD-GRS quartile (HR: 0.60, 95% CI: 0.44, 0.81) but not in women with a higher BMD-GRS.Conclusions: We observed significant effects of CaD intake on fracture risk only in women with the lowest genetic predisposition to low BMD. Future large-scale studies with functional characterization of GWAS findings are warranted to assess the utility of genetic risk score in analysis of risks and benefits of CaD for bone.

Genetic Screening of WNT4 and WNT5B in Two Populations with Deviating Bone Mineral Densities

A role for WNT4 and WNT5B in bone metabolism was indicated by genome-wide association studies (GWAS) and a Wnt4 knockout mouse model. The aim of this study was therefore to replicate and further investigate the causality between genetic variation in WNT4 and WNT5B and deviating bone mineral density (BMD) values. A WNT4 and WNT5B mutation screening was performed in patients with craniotubular hyperostosis using Sanger sequencing. Here, no putative causal mutations were detected. Moreover, a high and low BMD cohort was selected from the Odense Androgen Study population for re-sequencing. In WNT4 we detected four variants (three rare, one common), while in WNT5B we detected five variants (two rare, three common). For the common variants, no significant difference in genotype frequencies between the high and low BMD cohorts was observed. The SNPs associated with the GWAS were genotyped in these cohorts, but again no significant difference in genotype frequencies was observed. Despite the findings of the GWAS, we were not able to replicate or further verify the genetic association of polymorphisms in WNT4 and WNT5B with BMD. In order to do so, the intronic regions of both genes could be investigated more thoroughly in more extended populations (or extremes) with greater power. Future genetic and functional studies toward adjacent genes of WNT4 and WNT5B can also be interesting to figure out whether the signal from GWAS could possibly be attributed to genetic variation in these genes.

Osteoprotegerin Gene (OPG) Polymorphisms Associated with Peri-implantitis Susceptibility in a Chinese Han Population

Background

The aim of this study was to investigate the association between T950C (rs2073617) and G1181C (rs2073618) polymorphisms of the osteoprotegerin gene (OPG) and the susceptibility of peri-implantitis in the Chinese Han population.

Material/Methods

110 patients with peri-implantitis and 116 healthy persons from the Chinese Han population were included in this study using a case-control design; rs2073617 and rs2073618 in OPG were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The linkage disequilibrium (LD) and haplotype analysis were performed with Haploview software. Hardy-Weinberg equilibrium (HWE) was assessed in the control group based on the genotype distributions of OPG polymorphisms. The genotype, allele, and haplotype distribution differences between the case and control groups were analyzed by chi-square test, and the relative risk of PD was expressed by odds ratio (OR) and 95% confidence interval (CI).

Results

The study results showed that people carrying the CC genotype of rs2073618 were more likely to have peri-implantitis than GG genotype carriers (OR=2.18, 95% CI=1.03–4.62, p=0.04). In addition, patients with the C allele had 1.47 times the risk of suffering from peri-implantitis (OR=1.47, 95% CI=1.01–2.13, p=0.04), but not rs2073617 polymorphism. The G-C haplotype frequency of rs2073618-rs2073617 in OPG was significantly correlated to the increased susceptibility of peri-implantitis (OR=2.27, 95% CI=1.20–4.30).

Conclusions

OPG rs2073618 polymorphism may be related to the risk of peri-implantitis, but not rs2073617. Moreover, haplotype is also a non-ignorable risk factor.

Genome-Wide Association Study of Bone Mineral Density in Korean Men

Osteoporosis is a medical condition of global concern, with increasing incidence in both sexes. Bone mineral density (BMD), a highly heritable trait, has been proven a useful diagnostic factor in predicting fracture. Because medical information is lacking about male osteoporotic genetics, we conducted a genome-wide association study of BMD in Korean men. With 1,176 participants, we analyzed 4,414,664 single nucleotide polymorphisms (SNPs) after genomic imputation, and identified five SNPs and three loci correlated with bone density and strength. Multivariate linear regression models were applied to adjust for age and body mass index interference. Rs17124500 (p = 6.42 × 10^-7), rs34594869 (p = 6.53 × 10^-7) and rs17124504 (p = 6.53 × 10^-7) in 14q31.3 and rs140155614 (p = 8.64 × 10^-7) in 15q25.1 were significantly associated with lumbar spine BMD (LS-BMD), while rs111822233 (p = 6.35 × 10^-7) was linked with the femur total BMD (FT-BMD). Additionally, we analyzed the relationship between BMD and five genes previously identified in Korean men. Rs61382873 (p = 0.0009) in LRP5, rs9567003 (p = 0.0033) in TNFSF11 and rs9935828 (p = 0.0248) in FOXL1 were observed for LS-BMD. Furthermore, rs33997547 (p = 0.0057) in ZBTB and rs1664496 (p = 0.0012) in MEF2C were found to influence FT-BMD and rs61769193 (p = 0.0114) in ZBTB to influence femur neck BMD. We identified five SNPs and three genomic regions, associated with BMD. The significance of our results lies in the discovery of new loci, while also affirming a previously significant locus, as potential osteoporotic factors in the Korean male population.

Age dependent regulation of bone-mass and renal function by the MEPE ASARM-motif

CONTEXT

Mice with null mutations in matrix extracellular phosphoglycoprotein (MEPE) have increased bone mass, increased trabecular density and abnormal cancellous bone (MN-mice). These defects worsen with age and MEPE overexpression induces opposite effects. Also, genome wide association studies show that MEPE plays a major role in bone mass. We hypothesized that the conserved C-terminal MEPE ASARM-motif is chiefly responsible for regulating bone mass and trabecular structure.

DESIGN

To test our theory we overexpressed C-terminal ASARM-peptide in MN-mice using the Col1α1 promoter (MNAt-mice). We then compared the bone and renal phenotypes of the MNAt-mouse with the MN-mouse and the X-linked hypophosphatemic rickets mouse (HYP). The HYP mouse overexpresses ASARM-peptides and is defective for the PHEX gene.

RESULTS

The MN-mouse developed increased bone mass, bone strength and trabecular abnormalities that worsened markedly with age. Defects in bone formation were chiefly responsible with suppressed sclerostin and increased active β-catenin. Increased uric acid levels also suggested that abnormalities in purine-metabolism and a reduced fractional excretion of uric acid signaled additional renal transport changes. The MN mouse developed a worsening hyperphosphatemia and reduced FGF23 with age. An increase in the fractional excretion of phosphate (FEP) despite the hyperphosphatemia confirms an imbalance in kidney-intestinal phosphate regulation. Also, the MN mice showed an increased creatinine clearance suggesting hyperfiltration. A reversal of the MN bone-renal phenotype changes occurred with the MNAt mice including the apparent hyperfiltration. The MNAt mice also developed localized hypomineralization, hypophosphatemia and increased FGF23.

CONCLUSIONS

The C-terminal ASARM-motif plays a major role in regulating bone-mass and cancellous structure as mice age. In healthy mice, the processing and release of free ASARM-peptide are chiefly responsible for preserving normal bone and renal function. Free ASARM-peptide also affects renal mineral phosphate handling by influencing FGF23 expression. These findings have implications for understanding age-dependent osteoporosis, unraveling drug-targets and developing treatments.

Contributions of Caucasian-associated bone mass loci to the variation in bone mineral density in Vietnamese population

BACKGROUND AND AIM

Bone mineral density (BMD) is under strong genetic regulation, but it is not clear which genes are involved in the regulation, particularly in Asian populations. This study sought to determine the association between 29 genes discovered by Caucasian-based genome-wide association studies and BMD in a Vietnamese population.

METHODS

The study involved 564 Vietnamese men and women aged 18 years and over (average age: 47 years) who were randomly sampled from the Ho Chi Minh City. BMD at the femoral neck, lumbar spine, total hip and whole body was measured by DXA (Hologic QDR4500, Bedford, MA, USA). Thirty-two single nucleotide polymorphisms (SNPs) in 29 genes were genotyped using Sequenom MassARRAY technology. The magnitude of association between SNPs and BMD was analyzed by the linear regression model. The Bayesian model average method was used to identify SNPs that are independently associated with BMD.

RESULTS

The distribution of genotypes of all, but two, SNPs was consistent with the Hardy-Weinberg equilibrium law. After adjusting for age, gender and weight, 3 SNPs were associated with BMD: rs2016266 (SP7 gene), rs7543680 (ZBTB40 gene), and rs1373004 (MBL2/DKK1 gene). Among the three genetic variants, the SNP rs2016266 had the strongest association, with each minor allele being associated with ~0.02 g/cm(2) increase in BMD at the femoral neck and whole body. Each of these genetic variant explained about 0.2 to 1.1% variance of BMD. All other SNPs were not significantly associated with BMD.

CONCLUSION

These results suggest that genetic variants in the SP7, ZBTB40 and MBL2/DKK1 genes are associated with BMD in the Vietnamese population, and that the effect of these genes on BMD is likely to be modest.

LRP receptor family member associated bone disease

A dozen years ago the identification of causal mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene involved in two rare bone disorders propelled research in the bone field in totally new directions. Since then, there have been an explosion in the number of reports that highlight the role of the Wnt/β-catenin pathway in the regulation of bone homeostasis. In this review we discuss some of the most recent reports (in the past 2 years) highlighting the involvement of the members of the LRP family (LRP5, LRP6, LRP4, and more recently LRP8) in the maintenance of bone and their implications in bone diseases. These reports include records of new single nucleotides polymorphisms (SNPs) and haplotypes that suggest variants in these genes can contribute to subtle variation in bone traits to mutations that give rise to extreme bone phenotypes. All of these serve to further support and reinforce the importance of this tightly regulated pathway in bone. Furthermore, we discuss provocative reports suggesting novel approaches through inhibitors of this pathway to treat rarer diseases such as Osteoporosis-Pseudoglioma Syndrome (OPPG), Osteogenesis Imperfecta (OI), and Sclerosteosis/Van Buchem disease. It is hoped that by understanding the role of each component of the pathway and their involvement in bone diseases that this knowledge will allow us to develop new, more effective therapeutic approaches for more common diseases such as post-menopausal osteoporosis, osteoarthritis, and rheumatoid arthritis as well as these rarer bone diseases.