RESUMO
OBJECTIVE: This study aimed to determine the frequency of the PROGINS polymorphism in women with endometriosis-associated infertility, in infertile women without endometriosis and in controls. INTRODUCTION: The human progesterone receptor gene has two isoforms that modulate the biological action of progesterone: isoform A, which is capable of inhibiting the activation of the estrogen receptors, and isoform B, which has the capacity to activate the estrogen receptors. Several polymorphisms have been described for this gene, among which one stands out: a polymorphism named PROGINS, which has been speculated to be related to the genesis of endometriosis by several studies with conflicting results. METHODS: This was a prospective study that included 148 patients with endometriosis-associated infertility, 50 idiopathic infertile patients and 179 fertile women as controls. The PROGINS polymorphism was studied by PCR. RESULTS: Genotypes P1P1, P1P2 and P2P2 (P2 representing the PROGINS polymorphism) of the progesterone receptor gene presented frequencies of 93.9 percent, 5.4 percent and 0.7 percent, respectively, in the women with endometriosis-associated infertility (p=0.2101, OR=0.51, 95 percent CI=0.24-1.09); 94.4 percent, 4.2 percent and 1.4 percent, respectively, in the patients with minimal/mild endometriosis (p=0.2725, OR=0.53, 95 percent CI=0.20-1.43); 93.5 percent, 6.5 percent and 0 percent, respectively, among the patients with moderate/severe endometriosis (p=0.3679, OR=0.49, 95 percent CI=0.18-1.31); 86.0 percent, 14.0 percent and 0 percent, respectively, in idiopathic infertile women (p=0.8146, OR=1.10, 95 percent CI=0.46-2.63); and 88.3 percent, 10.6 percent and 1.1 percent, respectively, in the control group. CONCLUSION: The data suggest that PROGINS is not related either to endometriosis-associated infertility or to idiopathic infertility in the population studied.