Meta-analysis of the correlation between IL-6 -174 G/C polymorphism and polycystic ovarian syndrome

The role of TNF-α and il-6 SNP in polycystic ovary syndrome susceptibility

OBJECTIVE

Aim: To shed the light on the impact of TNF-α 1031 T/C (rs-1800629) and IL-6 174 G/C (rs1800795) polymorphism with disease susceptibility and development.

PATIENTS AND METHODS

Materials and Methods: A case-control study has been established based on 50 women with confirmed diagnosed polycystic ovarian syndrome, and 50 healthy controls. Allele specific PCR have been done in order to study SNP of TNF-alpha and IL-6 in both groups.

RESULTS

Result: The findings of the present investigation indicated that there was a signif i cant dif f erence in the frequency distribution of TNF-alpha 1031 T/C SNP according to genotype between patients and controls group p = 0.02. In addition, there is a high significant difference in the frequencies of distribution of alleles (T/C) between patients and control group p = 0.001. There was a signif i cant dif f erence in the frequency distribution of IL-6 174 G/C between patients and controls group p = 0.026. In addition, there is a signif i cant dif f erence in the frequencies of distribution of participants according to allele (G/C) between patients and control group p = 0.047. Genotype GC was significantly lower in patients' group and genotype GG was high significant in patients' group in comparison with a control group and the differences were significant, p = 0.024 and 0.006, respectively.

CONCLUSION

Conclusions: The present study concluded that IL-6 174 G/C, (rs:1800795) single nucleotide polymorphism (SNP) and TNF-alpha 1031 T/C (rs-1800629) were associated with PCOS susceptibility, and GG genotype in IL-6 and C allele in TNF are considered as risk factor.

Associations between IL-1α, IL-1β, TNFα, and IL-6 variations, and susceptibility to transposition of the great arteries

Background

To evaluate the relationship between IL-1α -889C/T (rs1800587), IL-1β -511C > T (rs16944), TNFα -308G > A (rs1800629), TNFα -238G > A (rs361525), IL-6 -174G > C (rs1800795), and IL-6 -572G > C (rs1800796) polymorphisms and the susceptibility to transposition of the great arteries (TGA).

Methods

A prospective analysis was performed on mothers whose newborns were diagnosed as having TGA. For each case of TGA, a mother who gave birth to a healthy neonate in the same period was randomly selected for the control group. The sample size was calculated before planning the study with 80% power and 5% alpha.

Results

Twenty-seven mothers whose newborn had TGA anomalies (group 1) and 27 mothers whose newborn had no TGA (group 2) were included in the study. There were no significant differences between the groups in terms of maternal age, pregestational body mass index, gestational age at birth and infant sex (p > 0.05). The genotype and allele distributions of IL-1α -889C/T (rs1800587), IL-1β -511C > T (rs16944), TNFα -308G > A (rs1800629), TNFα -238G > A (rs361525), IL-6 -174G > C (rs1800795) and IL-6 -572G > C (rs1800796) gene variants were not different between the two groups (p > 0.05).

Conclusions

There was no relation between IL-1α, IL-1β, IL-6, and TNFα promoter gene polymorphisms and TGA occurrence in our study group.

Trial registration: This present prospective case–control study was conducted in Baskent University Hospital, Ankara, Turkey, between May 2020 and November 2021. Ethical approval was obtained from the university’s Clinical Research Ethics Commitee (No: KA20/211) in accordance with the Declaration of Helsinki.

The Genetics of Polycystic Ovary Syndrome: An Overview of Candidate Gene Systematic Reviews and Genome-Wide Association Studies

Polycystic Ovary Syndrome (PCOS) is a complex condition with mechanisms likely to involve the interaction between genetics and lifestyle. Familial clustering of PCOS symptoms is well documented, providing evidence for a genetic contribution to the condition. This overview aims firstly to systematically summarise the current literature surrounding genetics and PCOS, and secondly, to assess the methodological quality of current systematic reviews and identify limitations. Four databases were searched to identify candidate gene systematic reviews, and quality was assessed with the AMSTAR tool. Genome-wide association studies (GWAS) were identified by a semi structured literature search. Of the candidate gene systematic reviews, 17 were of high to moderate quality and four were of low quality. A total of 19 gene loci have been associated with risk of PCOS in GWAS, and 11 of these have been replicated across two different ancestries. Gene loci were located in the neuroendocrine, metabolic, and reproductive pathways. Overall, the gene loci with the most robust findings were THADA, FSHR, INS-VNTR, and DENND1A, that now require validation. This overview also identified limitations of the current literature and important methodological considerations for future genetic studies. Much work remains to identify causal variants and functional relevance of genes associated with PCOS.

Association between rs1800795 polymorphism in the interleukin-6 gene and the risk of polycystic ovary syndrome: A meta-analysis

OBJECTIVE

Several published articles have investigated the association between the -174 G/C (rs1800795) polymorphism in the interleukin-6 (IL-6) gene and the risk of polycystic ovary syndrome (PCOS). However, the results were inconsistent. In the present study, a meta-analysis was performed to resolve this inconsistency.

METHODS

Eligible studies reporting an association between the IL-6 rs1800795 polymorphism and PCOS susceptibility were included from PubMed, Embase, Web of Science, and the Cochrane Library up to December 1, 2017. The odds ratio (OR) with the 95% confidence interval (CI) was used to calculate the strength of the associations. Publication bias detection was conducted using Begg test. We used STATA 11.0 software to perform the statistical analyses.

RESULTS

Six articles detailing case-control studies were included, reporting a total of 512 cases and 606 controls. The meta-analysis results indicated that rs1800795 was associated with decreased PCOS susceptibility in the overall population under the allelic model (G vs. C, OR = 0.59, 95% CI: 0.41-0.85, P = .005), the homozygous model (GG vs. CC, OR = 0.45, 95% CI: 0.28-0.73, P = .001), heterozygous model (GG vs. CG, OR = 0.50, 95% CI: 0.26-0.95, P = .036), and the dominant model (GC + CC vs. GG, OR = 0.48, 95% CI: 0.26-0.89, P = .020). However, a threshold P value of .05 was found under the recessive model (CC vs. GG + CG, OR = 0.62, 95% CI: 0.39-1.00).

CONCLUSIONS

This meta-analysis concluded that IL-6 rs1800795 polymorphism has a decreased association with PCOS risk among all populations studied. The results suggested that the IL-6 rs1800795 polymorphism is a protective factor for PCOS susceptibility. Given the limited ethnic groups and sample size, further studies are required to validate the association.