Polymorphisms in estrogen metabolism and estrogen pathway genes and the risk of miscarriage

This study investigated genetic variations in the estrogen pathway and their association with miscarriages. A total of 483 patients were recruited from a comprehensive control group for case-control studies. Three variants of the CYP19A1 gene (rs10046, rs4646 and rs700519) and one variant each of the estrogen (ESR1) and progesterone (PGR) receptor genes (rs3020314 and rs1042838) were investigated using polymorphism genotyping. The chi-squared test and one-way analysis of variation (ANOVA) were used for statistical analysis. For rs10046 (CYP19A1), the C/C genotype was associated with a greater frequency of miscarriages (P = 0.017). The other genotypes were not found to be associated with recurrent miscarriage. This is the first study that has identified a single-nucleotide polymorphism in the aromatase gene that suggests a significant association between genotypes and miscarriage. As aromatase is an essential enzyme in the estrogen pathway, it may be speculated that variations in the aromatase gene in some way give rise to different conditions in the endocrine environment that can lead to impaired fertility.