The progesterone receptor gene polymorphism, PROGINS, may be a factor related to the development of uterine fibroids.

Objective: To assess the possible association between the polymorphic allele of the progesterone receptor gene, named PROGINS, and uterine leiomyomas.

Design: Case-control study.

Setting: Department of Gynecology. Teaching hospital.

Patient(s): One hundred twenty-two premenopausal women with fibroids and 125 postmenopausal controls not presenting the disease.

Intervention(s): The subjects were classified as White or non-White (Black and Mulatto) and the progesterone receptor genotyping was performed, with DNA extracted from uterus in cases and from peripheric blood in controls and submitted to polymerase chain reaction (PCR) and agarose gel electrophoresis.

Main Outcome Measure(s): The presence of the PROGINS allele was recorded, and its frequency as well as the genotypic distribution among cases and controls were compared according to race.

Result(s): PROGINS-positive genotypes (heterozygous or mutant homozygous) were found in 19% of White and 11% of non-White women, and allelic frequency of PROGINS in the groups was 10.4% and 6.2%, respectively. Comparing patients and controls, we observed a significant difference among non-White women, both regarding presence of PROGINS-positive genotypes (4.9% vs. 25%, respectively), and PROGINS allele frequency (3.3% vs. 12.5%, respectively). There was no significant difference in PROGINS-positive genotypes among White cases and controls (16.4% vs. 20.6%, respectively), and in their allelic frequency (8.2% vs. 11.9%, respectively). The odds ratio showed reduced risk of fibroids related to PROGINS-positive genotypes in non-White women (odds ratio = 0.16, 95% confidence interval: 0.04-0.66), but not among White subjects (odds ratio = 0.76, 95% confidence interval: 0.33-1.74).

Conclusion(s): The PROGINS polymorphism revealed to be protective in terms of uterine fibroids in Brazilian non-White women.