Relation between progesterone receptor gene polymorphism, race, parity, and uterine leiomyoma occurrence

PURPOSE: to analyze race, parity and presence of the progesterone receptor polymorphism, named PROGINS, as factors related to uterine leiomyoma occurrence in Brazilian women. METHODS: we carried out a case-control study, composed of 122 patients with the diagnosis of uterine fibroid and 125 women without the disease. After recording the clinical data, we collected biological material for DNA extraction, polymerase chain reaction and agarose gel electrophoresis in order to identify the presence of PROGINS polymorphism. Statistical analysis was performed using the non-parametric Mann-Whitney test or the chi2 test, depending on the studied variable. The risk for the occurrence of the disease was calculated by the logistic regression model, providing the odds ratio (OR). The adopted significance level was 5% (p<0.05) and the confidence interval was 95% (95% CI). RESULTS: we observed a higher prevalence of non-whitewomen - mulatto and black - (50 vs 22.4%) and nulliparas (23.8 vs 11.2%) in the cases, while the progesterone receptor genotype was more often PROGINS positive - heterozygous or mutant homozygous - among the controls (21.6 vs 10.7%). The OR indicated an elevated risk for leiomyoma related to the non-whiterace (OR=3.46; 95% CI: 2.0-6.0) and the nulliparity (OR=3.30; 95% CI: 1.9-5.6), with reduction in the presence of PROGINS-positive genotypes (OR=0.43; 95% CI: 0.2-0.9). CONCLUSIONS: the non-whiterace and nulliparity were considered risk factors for the occurrence of uterine fibroid in the studied population, while PROGINS polymorphism showed to be a protective factor.OBJETIVOS: analisamos raça, paridade e presença do polimorfismo do gene do receptor de progesterona, denominado PROGINS, como fatores relacionados à ocorrência de leiomioma uterino em mulheres brasileiras. MÉTODOS: realizamos estudo caso-controle, no qual foram incluídas 122 pacientes com diagnóstico de leiomioma e 125 mulheres sem a doença. Após registro dos dados clínicos, coletamos material biológico para extração de DNA, reação em cadeia da polimerase e eletroforese em gel de agarose, a fim de identificar a presença do polimorfismo PROGINS. A análise estatística foi feita pelo teste não paramétrico de Mann-Whitney ou pelo teste do chi2, a depender da variável estudada. O risco para ocorrência da doença foi calculado pelo modelo de regressão logística, com obtenção da odds ratio (OR) (razão de chances). O nível de significância adotado foi de 5% (p