Association of 677 C>T (rs1801133) and 1298 A>C (rs1801131) polymorphisms in the MTHFR gene and breast cancer susceptibility: a meta-analysis based on 57 individual studies

Association between folate metabolism polymorphisms and breast cancer: a case-control study

We investigated the association between methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthetase (MTR A2756G), and methionine synthase reductase (MTRR A66G) polymorphisms involved in folate pathway and breast cancer risk, and the interaction between these polymorphisms and tobacco and alcohol consumption. Furthermore, we evaluated the association between these polymorphisms and clinicopathological variables. This case-control study included 606 Brazilian women, comprising 128 patients with breast cancer and 478 controls. MTHFR and MTR polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and MTRR polymorphisms using real-time PCR. Age ≥50 years (odds ratio [OR]: 2.65; 95% confidence interval [CI]: 1.65-4.26; p<0.001) and alcohol consumption (OR: 1.76; 95% CI: 1.0-2.85; p=0.021) were associated with an increased risk of breast cancer. For MTHFR A1298C, we observed a reduced risk of developing breast cancer in the codominant model (genotype CC-OR: 0.22; 95% CI: 0.06-0.74; p=0.014), recessive model (OR: 0.22; 95% CI: 0.07-0.76 p=0.004), and log-additive model (OR: 0.70; 95% CI: 0.49-0.98; p=0.035). Women aged ≥50 years and those who are alcohol consumers had increased susceptibility to breast cancer, and MTHFR A1298C modulated the risk for this disease. This is the first study to evaluate the association between polymorphisms in folate metabolism and breast cancer in the northwest region of São Paulo State, Brazil.

Effects of methylenetetrahydrofolate reductase single-nucleotide polymorphisms on breast, cervical, ovarian, and endometrial cancer susceptibilities

Background

Recent studies identifying methylenetetrahydrofolate reductase (MTHFR) polymorphisms associated with breast cancer (BC), ovarian cancer (OC), cervical cancer, and endometrial cancer (EC) have reported conflicting results and been underpowered. To clarify the correlation between MTHFR mutations and these common female malignancies, we conducted a comprehensive meta-analysis incorporating all eligible publications.

Methods

Relevant reports published before January 20, 2020, were retrieved from PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure databases. The odds ratio and 95% confidence interval summaries for the MTHFR 677C/T and 1298A/C polymorphisms in BC, OC, cervical cancer, and EC were estimated.

Results

A total of 171 studies comprising 56,675 cancer cases and 67,559 controls were included. The results showed a markedly elevated risk of cancer susceptibility related to MTHFR 677C/T based on all genetic models. Similarly, we identified a significant correlation between 1298A/C mutation and cancer risk based on overall comparisons among all models, except the heterozygous model. Moreover, subgroup analysis by cancer type revealed a significantly increased risk of BC associated with 677C/T in the five models and of cervical cancer associated with 1298A/C in some models. Based on ethnicity, significant associations were observed between Asian, African, and mixed populations for 677C/T and the Asian population for 1298A/C. With regard to the sample type used for analysis, we detected a positive association between using blood as the DNA source and cancer risk for 677C/T in all genetic models and for 1298A/C in some genetic models. Further stratification of the results revealed that a notably increased risk was associated with the use of polymerase chain reaction-restriction fragment-length polymorphism or TaqMan as the genotyping method, as well as with the use of population-or hospital-based groups as the controls for 677C/T and 1298A/C, respectively.

Conclusion

This meta-analysis suggests that MTHFR 677C/T and 1298A/C polymorphisms correlate with the risk of common gynecological cancers, with these findings potentially applicable for overall comparisons of related data.

MTHFR C677T and A1298C Polymorphisms in Breast Cancer, Gliomas and Gastric Cancer: A Review

Folate (vitamin B9) is found in some water-soluble foods or as a synthetic form of folic acid and is involved in many essential biochemical processes. Dietary folate is converted into tetrahydrofolate, a vital methyl donor for most methylation reactions, including DNA methylation. 5,10-methylene tetrahydrofolate reductase (MTHFR) is a critical enzyme in the folate metabolism pathway that converts 5,10-methylenetetrahydrofolate into 5-methyltetrahydrofolate, which produces a methyl donor for the remethylation of homocysteine to methionine. MTHFR polymorphisms result in reduced enzyme activity and altered levels of DNA methylation and synthesis. MTHFR polymorphisms have been linked to increased risks of several pathologies, including cancer. Breast cancer, gliomas and gastric cancer are highly heterogeneous and aggressive diseases associated with high mortality rates. The impact of MTHFR polymorphisms on these tumors remains controversial in the literature. This review discusses the relationship between the MTHFR C677T and A1298C polymorphisms and the increased risk of breast cancer, gliomas, and gastric cancer. Additionally, we highlight the relevance of ethnic and dietary aspects of population-based studies and histological stratification of highly heterogeneous tumors. Finally, this review discusses these aspects as potential factors responsible for the controversial literature concerning MTHFR polymorphisms.

Design and Evaluation of a Method for Testing Polymorphisms of Folate-Related Genes Using the Luminex Liquichip System

Purpose: The methylene tetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C, and the methionine synthase reductase (MTRR) A66G polymorphisms are the three most common folate metabolism-related loci in the Chinese population. They are associated with numerous birth defects or congenital diseases. To facilitate screening and genetic counseling, we established a method for the simultaneous detection of these three polymorphisms using the Luminex liquid suspension chip and multiple asymmetric polymerase chain reactions (PCRs). Materials and Methods: The three polymorphisms were amplified by multiplex PCR with biotinylated primers, followed by hybridization with six probe-linked magnetic microspheres. The mean fluorescent intensity value in each microsphere was detected by Luminex Magpix for polymorphism detection in 150 samples and confirmed by sequencing. Results: The consistency between the Luminex liquid suspension chip method and sequencing was 100%. Among the 150 randomized samples, the minor allele frequency (MAF) of MTHFR C677T was 0.41, which was the most common variant allele, followed by MTRR A66G (MAF = 0.24), and finally MTHFR A1298C (MAF = 0.19). Conclusion: The Luminex liquid suspension chip method can replace sequencing to analyze the MTHFR C677T, MTRR A1298C, and MTRR A66G loci simultaneously as a rapid, convenient, accurate, and stable method for large-scale testing.

Polymorphisms of MTHFR and TYMS predict capecitabine-induced hand-foot syndrome in patients with metastatic breast cancer

Background

Breast cancer is a global problem, and a large number of new cases are diagnosed every year. Capecitabine is effective in patients with metastatic breast cancer (MBC). Hand-foot syndrome (HFS) is a common adverse effect of capecitabine. In this study, we investigated the association between single nucleotide polymorphisms (SNPs) in genes involved in capecitabine metabolism pathways and capecitabine-induced HFS in Chinese patients with MBC to identify some predictive genetic biomarkers.

Methods

We selected 3 genes involved in capecitabine metabolism and screened genetic variants in these target genes. We genotyped a total of 22 SNPs in the thymidylate synthase gene (TYMS), the methylene tetrahydrofolate reductase gene (MTHFR), and the ribonucleotide reductase M1 gene (RRM1) in 342 MBC patients treated with capecitabine-based chemotherapy. The genotype distributions of each SNP in patients with and without HFS were assessed using Pearson’s χ² test, and the relationship between HFS and genotypes of SNPs was determined using logistic regression analysis. The association between SNPs and their corresponding gene expression was analyzed using the Blood expression quantitative trait loci (eQTL) browser online tools.

Results

We found 4 positive sites for HFS in the TYMS and MTHFR genes: TYMS rs2606241 (P = 0.022), TYMS rs2853741 (P = 0.019), MTHFR rs3737964 (P = 0.029), and MTHFR rs4846048 (P = 0.030). Logistic regression analyses showed that the genotype AG of MTHFR rs3737964 [odds ratio (OR) = 0.54, 95% confidence interval (CI) 0.31–0.97, P = 0.038] and MTHFR rs4846048 (OR = 0.54, 95% CI 0.30–0.98, P = 0.042) were protective factors of HFS, whereas the genotype CT of TYMS rs2853741 (OR = 2.25, 95% CI 1.31–3.87, P = 0.012) increased the risk of HFS. The association between the genotype GT of TYMS rs2606241 (OR = 1.27, 95% CI 0.73–2.23, P = 0.012) and HFS was uncertain. Further eQTL analyses confirmed that the alleles of rs3737964 and rs4846048 affected the gene expression levels of MTHFR in cis.

Conclusions

We have identified four potentially useful pharmacogenetic markers, TYMS rs2606241, TYMS rs2853741, MTHFR rs3737964, and MTHFR rs4846048 to predict capecitabine-induced HFS in MBC patients.

Frequencies of poor metabolizer alleles of 12 pharmacogenomic actionable genes in Punjabi Sikhs of Indian Origin

Diversity in drug response is attributed to both genetic and non-genetic factors. However, there is paucity of pharmacogenetics information across ethnically and genetically diverse populations of India. Here, we have analyzed 21 SNPs from 12 pharmacogenomics genes in Punjabi Sikhs of Indian origin (N = 1,616), as part of the Sikh Diabetes Study (SDS). We compared the allele frequency of poor metabolism (PM) phenotype among Sikhs across other major global populations from the Exome Aggregation Consortium and 1000 Genomes. The PM phenotype of CYP1A2*1 F for slow metabolism of caffeine and carcinogens was significantly higher in Indians (SDS 42%, GIH [Gujarati] 51%, SAS [Pakistani] 45%) compared to Europeans 29% (pgenotype = 5.3E-05). Similarly, South Asians had a significantly higher frequency of CYP2C9*3 (12% SDS, 13% GIH, 11% SAS) vs. 7% in Europeans (pgenotype = <1.0E-05) and 'T' allele of CYP4F2 (36%) SDS, (43%) GIH, 40% (SAS) vs. (29%) in Europeans (pgenotype = <1.0E-05); both associated with a higher risk of bleeding with warfarin. All South Asians -the Sikhs (0.36), GIH (0.34), and SAS (0.36) had a higher frequency of the NAT2*6 allele (linked with slow acetylation of isoniazid) compared to Europeans (0.29). Additionally, the prevalence of the low activity 'C' allele of MTHFR (rs1801131) was highest in Sikhs compared to all other ethnic groups [SDS (44%), GIH (39%), SAS (42%) and European (32%) (pgenotype = <1.0E-05)]. SNPs in MTHFR affect metabolism of statins, 5-fluorouracil and methotrexate-based cancer drugs. These findings underscore the need for evaluation of other endogamous ethnic groups of India and beyond for establishing a global benchmark for pre-emptive genotyping in drug metabolizing genes before beginning therapeutic intervention.

Genetic susceptibility to breast cancer risk associated with inorganic arsenic exposure

OBJECTIVE

To evaluate whether the association between breast cancer (BC) and inorganic arsenic (iAs) exposure is modulated by selected polymorphisms in iAs metabolism.

METHODS

A population based case-control (1016/1028) study was conducted in Northern Mexico. Urinary arsenic metabolites were measured by High Performance Liquid Chromatography. Metabolites percentages and methylation ratios, were estimated. Genotypes of selected polymorphisms were determined by allelic discrimination. The interaction between polymorphisms and iAs metabolites percentages and methylation ratios on BC was assessed with unconditional logistic regression models.

RESULTS

A significant interaction (p=0.002) between MTR c.2756A>G polymorphism and percentage dimethylarsinic acid (DMA) on BC was found; BC risk related with %DMA was lower in AG+GG carriers than in AA carriers. No other significant interactions were found.

CONCLUSION

MTR c.2756A>G polymorphism may confer protection for BC associated with iAs exposure. Further research is warranted to elucidate the potential involvement of other polymorphisms in iAs-related BC.

Association between MTHFR gene 1298A>C polymorphism and breast cancer susceptibility: a meta-analysis based on 38 case-control studies with 40,985 subjects

Background

Studies investigating the association between the methylenetetrahydrofolate reductase (MTHFR) gene 1298A>C polymorphism and the risk of breast cancer have reported inconsistent results. So, we performed this updated meta-analysis and tried to give a more precise estimation of association between MTHFR gene 1298A>C polymorphism and breast cancer susceptibility.

Methods

Relevant studies published before 1 January 2016 were identified by searching PubMed and EMBASE. The strength of relationship between the MTHFR gene 1298A>C polymorphism and breast cancer susceptibility was assessed using odds ratio (OR) and corresponding 95 % confidence interval (95 % CI). The meta-analysis was performed using Stata 11.0 software.

Results

A total number of 38 case-control studies including 18,686 cases and 22,299 controls were identified. No association was found in five genetic models (dominant model: OR = 0.99, 95 % CI 0.99–1.00, P = 0.218; recessive model: OR = 1.00, 95 % CI 0.97–1.02, P = 0.880; homozygote genetic model: OR = 0.99, 95 % CI 0.98–1.01, P = 0.390; heterozygote genetic model: OR = 0.99, 95 % CI 0.97–1.00, P = 0.138; and allele contrast genetic model: OR = 0.99, 95 % CI 0.98–1.01) for MTHFR gene 1298 A>C polymorphism and breast cancer susceptibility. In the subgroup analysis stratified by source of control, decreased risk of breast cancer was found in studies with hospital-based controls in dominant model (OR = 0.98, 95 % CI 0.96–1.00, P = 0.037).

Conclusions

Our meta-analysis suggested that there is no significant association between MTHFR gene 1298A>C polymorphism and breast cancer susceptibility for overall population.

Population-level diversity in the association of genetic polymorphisms of one-carbon metabolism with breast cancer risk

Aberrations in one-carbon metabolism were reported to increase breast cancer risk by influencing the DNA synthesis and methylation of DNA and catecholamines. However, the results of these association studies remain inconclusive. We have explored the contribution of eight genetic polymorphisms in modulating the susceptibility to breast cancer by performing a meta-analysis of worldwide studies. In total, 62 case-control studies representing 17 different populations involving 18,117 breast cancer cases and 23,573 healthy controls were included in this meta-analysis. Out of the eight polymorphisms analyzed, methylenetetrahydrofolate reductase (MTHFR) C677T exhibited positive association with the breast cancer risk in both fixed effects (OR 1.14, 95 % CI 1.10-1.17) and random effects (OR 1.10, 95 % CI 1.02-1.18) models. Solute carrier family 19 (folate transporter), member 1 (SLC19A1) G80A exhibited positive association (OR 1.16, 95 % CI 1.03-1.31) while MTR A2756G exhibited an inverse association (OR 0.78, 95 % CI 0.75-0.82) with the breast in fixed effect model alone. Significant heterogeneity was observed in the association of MTHFR C677T with breast cancer even between studies from the same geographical area, specifically among Chinese, Indians, and Turks. Subgroup analysis revealed MTHFR C677T-mediated breast cancer risk in post-menopausal women and women with low dietary intake of folate. Geographical area wise segregation of data revealed MTHFR-mediated increased breast cancer risk in populations who consume methionine-rich diet. Altitude-level variations were observed in the association of SHMT1 C1420T with breast cancer. India and Brazil of same altitude showed an inverse association with this polymorphism, while USA and China that share similar altitude showed a null association. MTHFR C677T and SLC19A1 G80A are the two polymorphisms of one-carbon metabolic pathway that increase breast cancer in the worldwide population. Dietary patterns and altitudinal variations are the likely risk modulators that are contributing toward ethnic- and population-level variations in genetic associations.

Potential biomarker panels in overall breast cancer management: advancements by multilevel diagnostics

Breast cancer (BC) prevalence has reached an epidemic scale with half a million deaths annually. Current deficits in BC management include predictive and preventive approaches, optimized screening programs, individualized patient profiling, highly sensitive detection technologies for more precise diagnostics and therapy monitoring, individualized prediction and effective treatment of BC metastatic disease. To advance BC management, paradigm shift from delayed to predictive, preventive and personalized medical services is essential. Corresponding step forwards requires innovative multilevel diagnostics procuring specific panels of validated biomarkers. Here, we discuss current instrumental advancements including genomics, proteomics, epigenetics, miRNA, metabolomics, circulating tumor cells and cancer stem cells with a focus on biomarker discovery and multilevel diagnostic panels. A list of the recommended biomarker candidates is provided.

Genetic Polymorphisms Analysis of Pharmacogenomic VIP Variants in Miao Ethnic Group of Southwest China

Background

Genetic polymorphisms have a potential clinical role in determining both inter-individual and inter-ethnic differences in drug efficacy, but we have not found any pharmacogenomics information regarding minorities, such as the Miao ethnic group. Our study aimed to screen numbers of the Miao ethnic group for genotype frequencies of VIP variants and to determine differences between the Miao and other human populations worldwide.

Material/Methods

In this study, we genotyped 66 Very Important Pharmacogene (VIP) variants selected from PharmGKB in 98 unrelated, healthy Miao individuals from the Guizhou province and compared our data with 12 other populations, including 11 populations from the HapMap data set and Xi’an Han Chinese.

Results

Using the χ² test, we found that the allele frequencies of the VDR rs1544410 and VKORC1 (rs9934438) variants in the Miao population are quite different from that in other ethnic groups. Furthermore, we found that genotype frequencies of rs1801133 (MTHFR) in the 13 selected populations are significantly different. Population structure and F-statistics (Fst) analysis show that the genetic background of the Miao is relatively close to that of Chinese in metropolitan Denver, CO, USA (CHD).

Conclusions

Our results help complete the information provided by the pharmacogenomics database of the Miao ethnic group and provide a theoretical basis for safer drug administration, which may be useful for diagnosing and treating diseases in this population.

Methylenetetrahydrofolate reductase gene C677T polymorphism and breast cancer risk: Evidence for genetic susceptibility

There are several evidences supporting the role of 5-10 methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in breast cancer (BC). Case control association studies on breast cancer have been repeatedly performed over the last two decades, but results are inconsistent. We performed a meta-analysis to confirm the association between MTHFR C677T polymorphism and BC risk. The articles were retrieved by searching the PubMed, Google Scholar, and Springer Link databases. Crude odds ratios (OR) with 95% confidence intervals (CIs) was used to assess the strength of association between C677T polymorphism and BC. Publication bias was assessed by Egger's and Begg-Mazumdar tests. Meta-analysis was performed with Open Meta Analyst. Total 75 studies with 31,315 cases and 35, 608 controls were found suitable for the inclusion in the present meta-analysis. The results of meta-analysis suggested that there were moderate significant association between C677T polymorphism and BC risk using overall comparisons in five genetic models (T vs. C: OR = 1.08, 95% CI = 1.03-1.13, p = < 0.001; TT + CT vs. CC: OR = 1.06, 95% CI = 1.02-1.09, p = < 0.001; TT vs. CC: OR = 1.17, 95% CI = 1.06-1.28, p = 0.001; CT vs. CC OR = 1.05, 95% CI = 1.01-1.08, p = 0.005; TT vs. CT + CC: OR = 1.12, 95% CI = 1.03-1.22, p = 0.005). In conclusion, results of present meta-analysis showed modest association between MTHFR C677T polymorphism with breast cancer in total studies. However, sub-group analysis results based on ethnicity showed strong significant association between TT genotype and breast cancer (TT vs. CC; OR°=°1.26; 95% CI: 1.06-1.51; p = 0.009) in Asian population but in Caucasian population such association was not observed (TT vs. CC; OR°=°1.08; 95% CI: 0.99-1.14; p = 0.05).

Association between the MTHFR C677T polymorphism and risk of cancer: evidence from 446 case-control studies

Many molecular epidemiological studies have been performed to explore the association between MTHFR C677T polymorphism and cancer risk in diverse populations. However, the results were inconsistent. Hence, we performed a meta-analysis to investigate the association between cancer risk and MTHFR C677T (150,086 cases and 200,699 controls from 446 studies) polymorphism. Overall, significantly increased cancer risk was found when all eligible studies were pooled into the meta-analysis. In the further stratified and sensitivity analyses, significantly increased breast cancer risk was found in Asians and Indians, significantly decreased colon cancer risk was found, significantly decreased colorectal cancer risk was found in male population, significantly increased gastric cancer risk was found in Caucasians and Asians, significantly increased hepatocellular cancer risk was found in Asians, significantly decreased adult acute lymphoblastic leukemia (AALL) risk was found in Caucasians, significantly decreased childhood acute lymphoblastic leukemia (CALL) risk was found in Asians, and significantly increased multiple myeloma and NHL risk was found in Caucasians. In summary, this meta-analysis suggests that MTHFR C677T polymorphism is associated with increased breast cancer, gastric cancer, and hepatocellular cancer risk in Asians, is associated with increased gastric cancer, multiple myeloma, and NHL risk in Caucasians, is associated with decreased AALL risk in Caucasians, is associated with decreased CALL risk in Asians, is associated with increased breast cancer risk in Asians, is associated with decreased colon cancer risk, and is associated with decreased colorectal cancer risk in male population. Moreover, this meta-analysis also points out the importance of new studies, such as Asians of HNC, Asians of lung cancer, and Indians of breast cancer, because they had high heterogeneity in this meta-analysis (I(2) > 75%).

MTHFR C677T polymorphism interaction with heavy alcohol consumption increases head and neck carcinoma risk

MTHFR C677T polymorphism has been indicated to be a risk factor for cancers, but its association with head and neck cancer (HNC) risk remains inconclusive. In the present study, we aimed to get a more precise estimation by performing a quantitative meta-analysis. Published papers up to Jun 2014 was searched and screened. Necessary information was rigorously extracted for data pooling and analyzing, and then, subgroup analyses on ethnicity, source of controls, sample size, tumor type, smoking and drinking status were also carried out. As a result, twenty-three case-control studies including 14298 subjects were included. The overall data failed to reveal a significant association between MTHFR C677T polymorphism and HNC risk (homozygote comparison model: OR = 1.16; 95%CI = 0.93-1.45; dominant model: OR = 1.05; 95%CI = 0.90-1.21; recessive model: OR = 1.14; 95%CI = 0.93-1.38). However, in the subgroup analysis about drinking status, increase risk was shown in the heavy drinking subgroup (TT vs CC: OR = 3.11; 95%CI = 1.52-3.02). In conclusion, the results of the present study suggest that Homozygous TT alleles of MTHFR C677T polymorphism might be a risk factor for HNC among individuals who have a heavy drinking history. Further studies are needed to get a more definitive conclusion.

MTHFR 677C>T polymorphism and the risk of breast cancer: evidence from an original study and pooled data for 28031 cases and 31880 controls

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) acts at an important metabolic point in the regulation of cellular methylation reaction. It assists in the conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. The latter aids in remethylation of homocysteine to de novo methionine that is required for DNA synthesis. The objective of this study was to examine the effect of MTHFR 677 C>T polymorphism on the risk of breast cancer in the Indian sub-continent.

METHODS AND RESULTS

We genotyped 677 C>T locus in 1096 individuals that were classified into cases (N=588) and controls (N=508). Genotype data were analyzed using chi-square test. No significant difference was observed in the distribution of genotypes between cases and controls in north Indian (P = 0.932), south Indian (P = 0.865), and pooled data (P = 0.680). To develop a consensus regarding the impact of 677C>T polymorphism on breast cancer risk, we also conducted a meta-analysis on 28031 cases and 31880 controls that were pooled from sixty one studies. The overall summary estimate upon meta-analysis suggested no significant correlation between the 677C>T substitution and breast cancer in the dominant model (Fixed effect model: OR = 0.97, P=0.072, Random effects model: OR = 0.96, P = 0.084) or the recessive model (Fixed effect model: OR = 1.05, P = 0.089; Random effects model: OR= 1.08, P= 0.067).

CONCLUSION

677 C>T substitution does not affect breast cancer risk in the Indo-European and Dravidian populations of India. Analysis on pooled data further ruled out association between the 677 C>T polymorphism and breast cancer. Therefore, 677 C>T substitution does not appear to influence the risk of breast cancer.

Association between RECQL5 genetic polymorphisms and susceptibility to breast cancer

Previous studies indicated that the RECQL5 gene polymorphism was associated with human cancers. However, the association of RECQL5 gene polymorphism with breast cancer remains unclear. In the present study, we investigated the association between polymorphisms of the RECQL gene and breast cancer in a Chinese population. We selected four polymorphisms of the RECQL5 gene (rs820186, rs820196, rs820200, and rs4789223) for the present study. The genotyping was performed using the TaqMan method in 510 patients with breast cancer and 510 age- and sex-matched non-cancer controls. We found that rs820196 and rs828200 polymorphisms of RECQL5 were associated with breast cancer. For rs820196, the CC genotype (16.7 vs 9.4 %, P < 0.001) and C allele (42.5 vs 34.3 %, P < 0.001) were common in the breast cancer patients than in the control subjects, respectively. For rs828200, the GG genotype (23.7 vs 18.0 %, P < 0.001) and G allele (52.7 vs 43.8 %, P < 0.001) were common in the breast cancer patients than in the control subjects, respectively. Haplotype analysis showed that C-G (odds ratio (OR) = 2.247, 95 % confidence interval (CI) 1.854∼2.722; P < 0.001) was associated with increased risk for breast cancer. However, the C-T (OR = 0.175, 95 % CI 0.110∼0.278; P < 0.001) and T-G (OR = 0.544; 95 % CI 0.428∼0.692; P < 0.001) were associated with decreased risk for breast cancer, respectively. The present study indicated that the RECQL5 genetic polymorphism and haplotypes were associated with breast cancer in a Chinese population.