Polymorphisms of transcription factor-7-like 2 (TCF7L2) gene in Tunisian women with polycystic ovary syndrome (PCOS)

Abstract

Background and aims: Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects women in their child-bearing age, and is often associated with insulin resistance and type 2 diabetes (T2DM). Given the overlap between PCOS and T2DM, we investigated the association of transcription factor-7-like 2 (TCF7L2) variants rs4506565, rs7903146, rs12243326, and rs12255372 with the susceptibility to PCOS.

Subjects and methods: Study subjects comprised 119 Tunisian women with PCOS (mean age 29.8±4.7years), and 150 control women (mean age 30.6±5.9years). TCF7L2 genotyping was done by the allelic discrimination/real-time PCR method.

Results: Minor allele frequencies (MAFs) of rs4506565 (P=0.61), rs7903146 (P=0.68), rs12243326 (P=0.56), and rs12255372 (P=0.60) were comparable between PCOS cases and control subjects. As the four tested TCF7L2 variants were in linkage disequilibrium, 4-locus (rs4506565, rs7903146, rs12243326, rs12255372) haplotype analysis demonstrated that haplotype 2111 was initially negatively associated with PCOS [P=0.035; OR (95% CI)=0.13 (0.02-0.85)], which was later lost upon correcting for multiple comparisons [Pc=0.248].

Conclusion: Our data suggest that there is weak or no contribution of TCF7L2 gene polymorphism to PCOS in Tunisian women. Further studies with larger samples are necessary to confirm this observation.

Keywords: BMI; HOMA-IR; HWE; Hardy–Weinberg equilibrium; Insulin resistance; MAF; PCOS; Replication; SNP; T2DM; TCF7L2; body-mass index; homeostasis model assessment for insulin resistance; minor allele frequency; polycystic ovary syndrome; single nucleotide polymorphism; transcription factor-7-like 2; type 2 diabetes.