-643C > T RANKL gene polymorphism is associated with osteoporosis in Tunisian postmenopausal women

Association of OPG and RANKL gene polymorphisms with bone mineral density in Indian women

Osteoprotegerin (OPG) and receptor activator of the NF-kB ligand (RANKL) are key players in bone remodelling. Reports show that OPG and RANKL gene polymorphisms are associated with osteoporosis and fracture risk. The aim of this study was to examine the influence of 5 single nucleotide polymorphisms (SNPs) in OPG and RANKL gene on bone mineral density (BMD) in Indian women. The study included 374 healthy Indian women. Kompetitive Allele Specific PCR (KASP) was used for genotyping. There was a significant difference in the BMD at spine between genotypes of OPG rs2073618 (CC: 0.988 ± 0.167 CG: 1.023 ± 0.17 GG: 1.053 ± 0.155; p = 0.039) which was lost upon adjustment for age and BMI (p = 0.087). Multiple linear regression revealed that genotypes of OPG rs2073618 (β = 0.098; p = 0.027) and rs3102735 (β = 0.092; p = 0.038) are predictors of BMD at spine in Indian women. We did not observe any association of SNPs in RANKL gene with BMD. Thus, SNPs rs2073618 and rs3102735 in OPG gene may influence BMD at spine in Indian women.

Osteoporotic hip and vertebral fractures in the Arab region: a systematic review

Asia is projected to account for the largest proportion of the rising burden of osteoporotic fractures worldwide. Data from the Middle East is scarce. We performed a systematic review on the epidemiology of vertebral and hip osteoporotic fractures in 22 Arab League countries, using Scopus, PubMed, and Embase. We identified 67 relevant publications, 28 on hip and 39 on vertebral fractures. The mean age of patients was 70-74 years, female to male ratio 1.2:2.1. Age-standardized incidence rates, to the UN 2010 population, were 236 to 290/100,000 for women from Kuwait and Lebanon, lower in Morocco. Risk factors for hip fractures included lower BMD or BMI, taller stature, anxiolytics, and sleeping pills. Most patients were not tested nor treated. Mortality derived from retrospective studies ranged between 10 and 20% at 1 year, and between 25 and 30% at 2-3 years. Among 39 studies on vertebral fractures, 18 described prevalence of morphometric fractures. Excluding grade 1 fractures, 13.3-20.2% of women, mean age 58-74 years, had prevalent vertebral fractures, as did 10-14% of men, mean age 62-74 years. Risk factors included age, gender, smoking, multiparity, years since menopause, low BMD, bone markers, high sclerostin, low IgF1, hypovitaminosis D, abdominal aortic calcification score, and VDR polymorphisms. Vertebral fracture incidence in women from Saudi Arabia, mean age 61, was 6.2% at 5 years, including grade 1 fractures. Prospective population-based fracture registries, prevalence studies, predictive models, fracture outcomes, and fracture liaison services from Arab countries are still lacking today. They are the pillars to closing the care gap of this morbid disease.

Analysis of the tumor necrosis factor superfamily member 11 gene polymorphism with bone mineral density and bone fracture frequency in patients with postmenopausal osteoporosis

PURPOSE

We aimed to examine the polymorphism of the promoter and exon 5 of the TNFSF11 gene and their impact on bone mineral density (BMD) and the frequency of bone fractures. TNFSF11 encodes the receptor activator of the NF-kB ligand (RANKL), a key regulator of bone metabolism and osteoporosis drug targets. BMD is an essential measure in diagnosing osteoporosis and assessing the risk of fractures. In vivo, RANKL expression research suggests that promoter TNFSF11 variants influence BMD. Moreover, exon 5 polymorphism of a linear epitope sequence for a denosumab could be related to the effectiveness of biological therapy.

PATIENTS AND METHODS

The study included 114 postmenopausal osteoporosis patients. BMD was measured in the lumbar spine and the femoral neck. Genetic analysis was performed using Sanger sequencing. Genotypes data for 263 female European population group were obtained from the 1000Genomes database.

RESULTS

We identified six promoter polymorphisms (rs9525641, rs9533155, rs9533156, rs11839112, rs28926171, rs183599708) and one silent TNFSF11 variant in exon 5 (rs9562415). Three of the sequence variants detected (rs9525641, rs9533155, rs9533156) proved to be polymorphic, whereas the others four occurred at a frequency below 2%. The statistical analysis demonstrated no significant differences between polymorphisms and BMD, and bone fractures. However, variant rs9533156 was relevant with the lumbar spine T-score (p = 0.0273), and no association with BMD was of borderline significance (p = 0.0529).

CONCLUSIONS

Variant rs9533156 may contribute to the genetic regulation of BMD in Polish postmenopausal osteoporosis, while the exon 5 sequence of the TNFSF11 gene is very conservative.

Association of Genetic Polymorphisms in TNFRSF11 with the Progression of Genetic Susceptibility to Gastric Cancer

Objective

To investigate the relationship between polymorphism of TNFRSF11 gene rs9533156 and rs2277438 and susceptibility to gastric cancer.

Methods

A case-control study was conducted to select 577 cases of primary gastric cancer and 678 cases of normal control. We extracted whole blood genomic DNA and amplified the target gene fragment by PCR. The genotyping and allele were tested through the snapshot method.

Results

In this case-control study, we observed that there was a difference in the genotype distribution of TNFRSF11 gene rs9533156 between the case group and the control group. The frequency distribution of TC heterozygous mutation in the case group was higher than that in the control group. The smoking rate in the case group (34.49%) was higher than that in the control group (27.29%), and the difference in frequency distribution between the two groups was statistically significant (P=0.006). Our findings suggest that TNFRSF11 rs9533156 is associated with susceptibility to GC, which is more evident among elderly patients (>62 years), nonsmokers, and patients who do not consume alcohol. The analysis of the relationship between the TNFSF11 gene rs9533156 site variant and clinical factors of gastric cancer showed that, compared with the tumor size <2 cm group, patients with tumor size ≥2 cm and whom carrying rs9533156 site mutations had a higher frequency distribution, and the difference was statistically significant (P=0.022). Compared with the nonhyperglycemic group, the frequency distribution of patients with rs9533156 site mutations in the diabetes group was higher, and the difference was statistically significant (P < 0.001).

Conclusion

This study shows that there is a correlation between smoking and the occurrence of gastric cancer. Based on our research, the functional SNP TNFRSF11 TC genotype may be an indicator of individual susceptibility to GC. The mutation at rs9533156 may be related to the size of gastric cancer. The mutation rate of rs9533156 of TNFSF11 gene is higher in diabetic gastric cancer patients.

RANKL Gene Polymorphism as a Potential Biomarker to Identify Acute Charcot Foot Among Indian Population With Type 2 Diabetes: A Preliminary Report

Studies addressing the link between gene polymorphism and Charcot neuropathic osteoarthopathy (CN) have been limited to analyse osteoprotegerin gene. Aim is to understand the association of RANKL gene variants on the susceptibility of diabetic neuropathy and CN and to measure the serum levels of sRANKL among Indian population with type 2 diabetes. 77 subjects (48 males: 29 females) were recruited and divided into 3 groups. Group 1 Control: normal glucose tolerance (NGT). Group 2: Type 2 diabetes mellitus and neuropathy (DPN). Group 3: Established type 2 diabetes mellitus, DPN, and CN. Subjects were genotyped for RANKL SNP 693 C/G and 643 C/T using polymerase chain reaction-restriction fragment length polymorphism. sRANKL levels were measured using ELISA (enzyme-linked immunosorbent assay). The serum levels of sRANKL were significantly different between the 3 groups. In RANKL -643 C/T the frequency of “CT” genotype and the minor allele “T” was greater among the DPN and CN group compared with the NGT. Further statistical analysis found a significant difference in genotypic frequencies between DPN and NGT subjects with CT genotype. In RANK L -693 C/G the frequency of homozygote mutant “GG” and the minor allele “G” was greater among the DPN and CN group compared with the NGT. Significant differences in genomic frequencies were observed among “GG” genotype. RANKL -643 C/T was significantly associated with DPN alone while -693 C/G was significantly associated with both DPN and CN. Thus, the study suggests RANKL polymorphism might be considered as an independent risk factor for the development of CN.

Selected RANKL/RANK/OPG system genetic variants in diabetic foot patients

Purpose

Diabetic foot is a complication of long-lasting diabetes mellitus affecting up to 15% of patients, both in type 1 and type 2 diabetes. Osteoprotegerin is involved in osteogenesis and calcification. The aim of the study was to assess the role of selected osteoprotegerin gene variants in diabetes patients with diabetic foot.

Methods

The study involved 300 patients with diabetes and diabetic foot and 968 healthy controls. The study group was formed by 243 patients with diabetic foot of neuropathic origin, 102 with diabetic foot of neuroischemic origin and 77 with Charcot neuroarthropathy.

Results

Compared to controls, rs1872426 and rs1485286 showed correlation with diabetic foot in diabetes subjects. Significant associations between rs2073618, rs1872426, rs7464496 and rs1485286 in men were reported. The aforementioned correlations were also present in type 2 diabetes patient subgroup. Variant rs1485286 was associated to diabetic foot of neuropathic origin. Sex-specificity for females was present for rs6993813 in patients with diabetic foot of neuropathic origin and type 1 diabetes. Variants rs1872426, rs2073617 and rs1485286 were correlated with CN. We found that age, body weight, body mass index, waist circumference, hip circumference and waist-hip ratio were among the basic risk factors of diabetic foot.

Conclusions

The following variants TNFRSF11B (rs2073618, rs2073617, rs1872426, rs1032128, rs7464496, rs11573829 and rs1485286), COLEC10 (rs6993813, rs3134069) and TNFSF11 (rs9533156) present differences in allele frequencies in diabetic foot patients and show correlation with gender, diabetes type and diabetic foot etiology.