Polymorphisms in the estrogen receptor α gene and reproductive axis in women
Olga Ianas1, Dana Manda1, Lorand Savu2, Suzana Vladoiu1, Oana Popa1, Roxana Rosca1,3 & Carmen Iordachescu1
Background: ER-α gene (ESR1) polymorphisms have been associated with a variety of disorders including human infertility. In this study, we examined two polymorphisms of the estrogen receptor α (ESR1) gene, IVS-1 −397 T/C (dbSNP: rs2234693) and IVS-1 −351 A/G (dbSNP: rs9340799) in a sample of healthy women of reproductive age to determine whether are associated with hormonal levels for a better understanding of its biological actions in human development, with special emphasis on the reproductive process.
Subjects and methods: Women (168) of age between 20 and 40 years, without significant medical illness participated as volunteers in this study that had the ethical committee approval. Total morning levels of serum estradiol, estrone, 17-OHP, DHEA, DHEAS, androstendion, progesterone, testosterone, free testosterone, DHT, SHBG, inhibins: A and B, LH, FSH and Prl were measured. PvuII and XbaI polymorphisms were analyzed by polymerase chain reaction restriction fragment lengths polymorphism (PCR-RFLP).
Results: The percentages of genotype distribution for XbaI were 45.8-AA, 42.2-AG, 13-GG and PvuII: 32.5-TT, 41.0-TC, 26.5-TT respectively. XbaI polymorphism was associated with prolactin (χ2=10.81; P=0.004) and DHEA (χ2=6.57; P=0.038); the levels of estradiol (P=0.015), progesterone (P=0.013), SHBG (P=0.034) and inhibin A (P=0.038) were higher in GG genotype. PvuII polymorphism was associated with prolactin (χ2=14.99; P=0.001), DHEA (χ2=8.80; P=0.012) and FEI (bioavailable estradiol) (χ2=6.40; P=0.041). Estradiol levels were higher (P=0.010) in CC genotype; estrone (P=0.023), DHT (0.013) was lower and SHBG was higher (P=0.24) in heterozygote.
Conclusion: The findings of this study support the view that ESR1 polymorphisms may affect reproductive function through differences in hormonal secretion in women.
Supported by PNII no. 41-014/2007, Ministry of Education and Research.