Background: ANRIL rs4977574 gene polymorphism has been associated with arterial thrombosis and cardiovascular disease development. ANRIL rs4977574 gene polymorphism could also be associated with recurrent pregnancy loss (RPL) since there is increasing evidence in favor of a potential shared pathophysiological mechanism with cardiovascular disease, potentially through arterial thrombosis. This study's goal is to investigate the differences in ANRIL rs4977574 gene polymorphism between women with and without RPL, if any, as well as a potential association with the number of pregnancy losses.
Methods: DNA was isolated from peripheral blood samples, and the sequence containing the polymorphism of interest was amplified with PCR. Results were visualized under UV light following electrophoresis in 3% agarose gel with ethidium bromide. ANRIL rs4977574 (A>G) prevalence was compared between 56 women with and 69 without RPL. Results were adjusted for women's age and BMI, while a stratified analysis was performed according to number of pregnancy losses.
Results: Allele A was significantly more prevalent in the control group compared to RPL women [31 (44.9%) vs. 14 (25%), p = 0.021]. Although not reaching statistical significance, a gradually decreasing prevalence of allele A with an increasing number of pregnancy losses was observed [31 (44.9%) in control, eight (30.7%) with two, six (23.1%) with three, and 0 (0.0%) with four pregnancy losses, p = 0.078]. Results were also similar following adjustment.
Conclusions: This is the first study that demonstrates an association between RPL presence and ANRIL rs4977574 gene polymorphism (lower prevalence of allele A), while a difference according to the number of pregnancy losses cannot be excluded.
Keywords: ANRIL; polymorphism; pregnancy loss; recurrent pregnancy loss; rs4977574.