Infertility caused by an association between Arg72Pro polymorphism of the p53 gene and Glu298Asp of the eNOS gene in patients with endometriosis
Endometriosis is characterized by ectopic endometrial tissue and affects millions of women worldwide. The disease leads to various symptoms such as chronic pelvic pain and infertility and does not yet have a well-defined etiology. The pathology is similar to cancer, since endometrial cells are highly proliferative, invade tissues and may be associated with tumor suppressor genes, including p53. Genetic polymorphisms are responsible for phenotypic variations in the population and the development of endometriosis is due to a combination of multiple genes and environmental factors. The Arg72Pro polymorphism of the p53 gene alters the amino acid 72 from arginine to proline and studies indicate that there is a considerable increase in the risk of cancer in patients with this polymorphism, because the protein becomes more susceptible to degradation. The eNOS gene participates in angiogenesis, a necessary factor for endometrial cells to survive outside the uterus and has increased expression in patients with endometriosis during the menstrual cycle. The Glu298Asp eNOS polymorphism is due to a point mutation of glutamate to aspartate, which can generate changes in its enzymatic activity. Aspartate generates protein products with different susceptibility to cleavage, functionally affecting the protein. We detected the Arg72Pro polymorphism of p53 and the Glu298Asp polymorphism of eNOS and estimated their prevalence in fertile and infertile patients diagnosed with endometriosis. The techniques used were conventional PCR and ARMS-PCR. Patients with Pro or Asp polymorphic alleles were found to be more susceptible to the development of endometriosis, and an association of these two polymorphisms is directly linked to infertility. The target genes p53 and eNOS can be used as molecular markers for endometriosis diagnosis, guiding prognosis and treatment, and may contribute to a better understanding of the pathophysiology of endometriosis.