rs1800734: matüration arrestine bağlı nonobstrüktif azoospermi için bir risk aleli

Year 2026, Volume: 79 Issue: 1 , 82 - 88 , 27.03.2026

Yasemin Ülger , Kaan Aydos , Timur Tuncalı

https://doi.org/10.65092/autfm.1767777

https://izlik.org/JA68XF77ER

Abstract

Arka Plan: Erkek interfilitesi, önemli bir üreme sağlığı sorunu olmasının yanı sıra, genel erkek sağlık durumunun bir biyolojik belirteci olarak giderek daha fazla kabul görmektedir. Nonobstrüktif azoospermi (NOA) hastaları, en kötü sağlık durumunun ve kansere yakalanma riskinin en yüksek olduğu gruptur. Kanser duyarlılık geni olan MLH1’in, mayoz bölünme sırasında homolog rekombinasyonda rol oynadığı iyi bilinmektedir. Mlh1 mutant farelerde, mayoz arresti ile birlikte azoospermi görülmüştür.

Amaç: Bu çalışmada MLH1 geninin erkek infertilitesiyle de ilişkili olup olmadığını daha ayrıntılı olarak araştırmak amacıyla, nonobstrüktif azoospermiye bağlı matürasyon arresti (MA) olan erkeklerde MLH1 genindeki risk alelerini saptamayı amaçladık.

Olgular ve Metodlar: MA olan 42 hastada MLH1 varyantlarının genotipleri belirlendi. Önemi olan varyantlar daha sonra GnomAD v.3.1.2 (kanser dışı) erkek popülasyon veritabanı ve bir ulusal genetik hastalık değerlendirme merkezinin (UGHDM) ekzom veri deposu ile karşılaştırıldı.

Bulgular: rs1800734 alel frekansı, GnomAD'a (p<0,001) kıyasla hasta grubunda anlamlı olarak daha yüksek saptandı (odds oranı (OR): 2,3 (1,5-3,5)) ve UGHDM 'nin ekzom verilerine (p=0,002) kıyasla OR: 2 (1,3-3,1) idi. Rs1800734 için homozigot genotip, GnomAD (p<0,001) OR: 5 (2,24-11) ve ekzom verilerine (p=0,010) kıyasla OR: 3,3 (1,4-7,5) ile hasta grubunda anlamlı olarak daha yüksek saptandı.

Sonuç: Bu çalışmada, rs1800734'ün MA ile ilişkili NOA için bir risk aleli olduğu tespit edilmiştir. Rs1800734'ün MLH1 promoter hipermetilasyonu ile ilişkili olduğu bilinmektedir. MLH1 promoter hipermetilasyonunun oligozoospermili erkeklerde arttığı gösterilmiştir, bu nedenle rs1800734 açısından azoospermi için de karsinogenezde aynı mekanizma mevcut olabileceği düşünülmüştür.

Keywords

rs1800734 , MLH1 , Nonobstrüktif azoospermi , matürasyon arresti , erkek infertilitesi

Project Number

220S004

rs1800734: a risk allele for nonobstructive azoospermia related to maturation arrest

https://izlik.org/JA68XF77ER

Abstract

Background: Male infertility is increasingly being conceived as a biomarker of general male health status other than being a significant reproductive health issue. Nonobstructive azoospermia (NOA) patients have the worst health status impairment as well as highest risk of developing cancer. It’s well known that cancer susceptibility gene, MLH1 have roles in homologous recombination during meiosis. Mlh1 mutant mice have azoospermia with meiotic arrest.

Aim: We aimed to identify risk alleles in MLH1 gene in males with nonobstructive azoospermia related maturation arrest (MA) to investigate further whether this cancer susceptibility gene is also related to male infertility.

Patients and Methods: MLH1 variants were genotyped in 42 patients with MA. The variants of interest then compared to GnomAD v.3.1.2 (non-cancer) male population database and to the repository exome data of a national genetic disease evaluation center (NGDEC).

Results: rs1800734 allele frequencies were significantly higher in the patient group compared to GnomAD (p<0.001) with odds ratio (OR):2.3 (1.5-3.5), and to the exome data of NGDEC (p=0.002) with OR:2 (1.3-3.1). Homozygous genotype for rs1800734 was significantly higher in the patient group compared to the GnomAD (p<0.001) with OR: 5 (2.24-11) and to the exome data (p=0.010) with OR: 3.3 (1.4-7.5).

Conclusion: In this study we found rs1800734 is a risk allele for NOA related to MA. It is known that rs1800734 is related to hypermethylation of MLH1 promoter. As MLH1 hypermethylation has been shown to be increased in oligozoospermic males, the same mechanism in carcinogenesis may also exist for azoospermia in the context of rs1800734.

Keywords

rs1800734 , MLH1 , nonobstructive azoospermia , maturation arrest , male infertility

Ethical Statement

The study protocol was approved by the Ethics Committee of Ankara University School of Medicine (reference number: İ4-210-20) and performed according to the Declaration of Helsinki.

Supporting Institution

TÜBİTAK

Project Number

220S004

References

• Jarvi K, Lo K, Fischer A, Grantmyre J, Zini A, Chow V, et al. CUA guideline: The workup of azoospermic males. J Can Urol Assoc 2010;4:163–7. doi:10.5489/cuaj.10050.
• Ventimiglia E, Capogrosso P, Boeri L, Serino A, Colicchia M, Ippolito S, et al. Infertility as a proxy of general male health: results of a cross-sectional survey. Fertil Steril 2015;104:48–55. doi:10.1016/J.FERTNSTERT. 2015.04.020.
• Del Giudice F, Kasman AM, Ferro M, Sciarra A, De Berardinis E, Belladelli F, et al. Clinical correlation among male infertility and overall male health: A systematic review of the literature. Investig Clin Urol 2020;61:355–71. doi:10.4111/ICU.2020.61.4.355.
• Boeri L, Ventimiglia E, Cazzaniga W, Pederzoli F, Fallara G, Pozzi E, et al. Risk of health status worsening in primary infertile men: A prospective 10-year follow-up study. Andrology 2022;10:128–36. doi:10.1111/ ANDR.13090.
• Del Giudice F, Kasman AM, Li S, Belladelli F, Ferro M, de Cobelli O, et al. Increased Mortality Among Men Diagnosed With Impaired Fertility: Analysis of US Claims Data. Urology 2021;147:143–9. doi:10.1016/J.UROLOGY.2020.07.087.
• Nagirnaja L, Aston KI, Conrad DF. The Genetic Intersection of Male Infertility and Cancer. Fertil Steril 2018;109:20. doi:10.1016/J.FERTNSTERT. 2017.10.028.
• Ndou L, Chambuso R, Algar U, Boutall A, Goldberg P, Ramesar R. Genomic Medicine in the Developing World: Cancer Spectrum, Cumulative Risk and Survival Outcomes for Lynch Syndrome Variant Heterozygotes with Germline Pathogenic Variants in the MLH1 and MSH2 Genes. Biomedicines 2024;12. doi:10.3390/BIOMEDICINES12122906.
• Codina-Pascual M, Oliver-Bonet M, Navarro J, Campillo M, García F, Egozcue S, et al. Synapsis and meiotic recombination analyses: MLH1 focus in the XY pair as an indicator. Hum Reprod 2005;20:2133–9. doi:10.1093/HUMREP/DEI023.
• Baker SM, Plug AW, Prolla TA, Bronner CE, Harris AC, Yao X, et al. Involvement of mouse Mlh1 in DNA mismatch repair and meiotic crossing over. Nat Genet 1996;13:336–42. doi:10.1038/ng0796-336.
• Edelmann W, Cohen PE, Kane M, Lau K, Morrow B, Bennett S, et al. Meiotic pachytene arrest in MLH1-deficient mice. Cell 1996;85:1125–34. doi:10.1016/S0092-8674(00)81312-4.
• Gonsalves J, Sun F, Schlegel PN, Turek PJ, Hopps C V., Greene C, et al. Defective recombination in infertile men. Hum Mol Genet 2004;13:2875–83. doi:10.1093/hmg/ddh302.
• Nudell D, Castillo M, Turek PJ, Pera RR. Increased frequency of mutations in DNA from infertile men with meiotic arrest. Hum Reprod 2000;15:1289–94. doi:10.1093/humrep/15.6.1289.
• Enguita-Marruedo A, Sleddens-Linkels E, Ooms M, de Geus V, Wilke M, Blom E, et al. Meiotic arrest occurs most frequently at metaphase and is often incomplete in azoospermic men. Fertil Steril 2019;112:1059-1070. e3. doi:10.1016/j.fertnstert.2019.08.004.
• Colpi GM, Colpi EM, Piediferro G, Giacchetta D, Gazzano G, Castiglioni FM, et al. Microsurgical TESE versus conventional TESE for ICSI in non-obstructive azoospermia: a randomized controlled study. Reprod Biomed Online 2009;18:315–9. doi:10.1016/S1472-6483(10)60087-9.
• Zhang X, Ding M, Ding X, Li T, Chen H. Six polymorphisms in genes involved in DNA double-strand break repair and chromosome synapsis: Association with male infertility. Syst Biol Reprod Med 2015;61:187–93. doi:10.3109/19396368.2015.1027014.
• Zhao X, Mu C, Ma J, Dai X, Jiao H. The association of four SNPs in DNA mismatch repair genes with idiopathic male infertility in northwest China. Int J Immunogenet 2019;46:451–8. doi:10.1111/IJI.12448.
• Gunes S, Agarwal A, Henkel R, Mahmutoglu AM, Sharma R, Esteves SC, et al. Association between promoter methylation of MLH1 and MSH2 and reactive oxygen species in oligozoospermic men-A pilot study. Andrologia 2018;50. doi:10.1111/AND.12903.
• Ito E, Yanagisawa Y, Iwahashi Y, Suzuki Y, Nagasaki H, Akiyama Y, et al. A core promoter and a frequent single-nucleotide polymorphism of the mismatch repair gene hMLH1. Biochem Biophys Res Commun 1999; 256:488–94. doi:10.1006/BBRC.1999.0368.
• Ma G, Ge Y, Gu D, Du M, Chu H, Chen J, et al. Functional annotation of colorectal cancer susceptibility loci identifies MLH1 rs1800734 associated with MSI patients. Gut 2016;65:1227–8. doi:10.1136/GUTJNL- 2016-311543.
• Funck A, Santos JC, Silva-Fernandes IJL, Rabenhorst SHB, Martinez CAR, Ribeiro ML. Effect of MLH1 -93G>A on gene expression in patients with colorectal cancer. Med Oncol 2014;31:1–5. doi:10.1007/S12032-014-0160-Z.
• Mei M, Liu D, Dong S, Ingvarsson S, Goodfellow PJ, Chen H. The MLH1 -93 promoter variant influences gene expression. Cancer Epidemiol 2010;34:93–5. doi:10.1016/J.CANEP.2009.12.009.
• Miyakura Y, Tahara M, Lefor AT, Yasuda Y, Sugano K. Haplotype definedby the MLH1-93G/A polymorphism is associated with MLH1 promoter hypermethylation in sporadic colorectal cancers. BMC Res Notes 2014;7. doi:10.1186/1756-0500-7-835.
• Chen H, Taylor NP, Sotamaa KM, Mutch DG, Powell MA, Schmidt AP, et al. Evidence for heritable predisposition to epigenetic silencing of MLH1. Int J Cancer 2007;120:1684–8. doi:10.1002/IJC.22406.
• Savio AJ, Mrkonjic M, Lemire M, Gallinger S, Knight JA, Bapat B. The dynamic DNA methylation landscape of the mutL homolog 1 shore is altered by MLH1-93G>A polymorphism in normal tissues and colorectal cancer. Clin Epigenetics 2017;9. doi:10.1186/S13148-017-0326-6.
• Liu NQ, Ter Huurne M, Nguyen LN, Peng T, Wang SY, Studd JB, et al. The non-coding variant rs1800734 enhances DCLK3 expression through long-range interaction and promotes colorectal cancer progression. Nat Commun 2017;8. doi:10.1038/NCOMMS14418.
• Savio AJ, Bapat B. Modulation of transcription factor binding and epigenetic regulation of the MLH1 CpG island and shore by polymorphism rs1800734 in colorectal cancer. Epigenetics 2017;12:441–8. doi:10.108 0/15592294.2017.1305527.
• Perera S, Mrkonjic M, Rawson JB, Bapat B. Functional effects of the MLH1-93G>A polymorphism on MLH1/EPM2AIP1 promoter activity. Oncol Rep 2011;25:809–15. doi:10.3892/OR.2010.1129.
• Mrkonjic M, Roslin NM, Greenwood CM, Raptis S, Pollett A, Laird PW, et al. Specific variants in the MLH1 gene region may drive DNA methylation, loss of protein expression, and MSI-H colorectal cancer. PLoS One 2010;5. doi:10.1371/JOURNAL.PONE.0013314.
• Pongsavee M, Wisuwan K, Pongsavee K. MLH1 rs1800734 Pathogenic Variant among Patients with Colorectal Cancer in the Lower Northeastern Region of Thailand. Asian Pac J Cancer Prev 2023;24:2911–6. doi:10.31557/APJCP.2023.24.8.2911.
• Allan JM, Shorto J, Adlard J, Bury J, Coggins R, George R, et al. MLH1 -93G>A promoter polymorphism and risk of mismatch repair deficient colorectal cancer. Int J Cancer 2008;123:2456–9. doi:10.1002/IJC.23770.
• Das AP, Chaudhary N, Tyagi S, Agarwal SM. Meta-Analysis of 49 SNPs Covering 25,446 Cases and 41,106 Controls Identifies Polymorphisms in Hormone Regulation and DNA Repair Genes Associated with Increased Endometrial Cancer Risk. Genes (Basel) 2023;14. doi:10.3390/ GENES14030741.
• Rodriguez-Hernandez I, Perdomo S, Santos-Briz A, Garcia JL, Gomez- Moreta JA, Cruz JJ, et al. Analysis of DNA repair gene polymorphisms in glioblastoma. Gene 2014;536:79–83. doi:10.1016/J.GENE.2013.11.077.
• Nogueira GAS, Lourenço GJ, Oliveira CBM, Marson FAL, Lopes-Aguiar L, Costa EFD, et al. Association between genetic polymorphisms in DNA mismatch repair-related genes with risk and prognosis of head and neck squamous cell carcinoma. Int J Cancer 2015;137:810–8. doi:10.1002/ IJC.29435.
• Zhu H, Li X, Zhang X, Chen D, Li D, Ren J, et al. Polymorphisms in mismatch repair genes are associated with risk and microsatellite instability of gastric cancer, and interact with life exposures. Gene 2016;579:52–7. doi:10.1016/J.GENE.2015.12.050.
• Richards S, Aziz N, Bale S, Bick D, Das S, Gastier-Foster J, et al. Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med 2015;17:405–24. doi:10.1038/GIM.2015.30.
• Schmidt RJ, Steeves M, Bayrak-Toydemir P, Benson KA, Coe BP, Conlin LK, et al. Recommendations for risk allele evidence curation, classification, and reporting from the ClinGen Low Penetrance/Risk Allele Working Group. Genet Med 2024;26. doi:10.1016/J.GIM.2023.101036.