Links between SNPs in TLR-2 and TLR-4 and idiopathic recurrent pregnancy loss.

Background: Recurrent pregnancy loss is a serious complication of pregnancy and failure of the innate immune system, one part of which are toll-like receptors (TLRs). We hypothesised links between variants of TLR-2 and TLR-4 with recurrent pregnancy loss.Subjects and methods: We recruited 335 women with recurrent pregnancy loss, defined as ≥3 consecutive spontaneous miscarriage of unknown aetiology, and 331 age-matched control women. TLR-2 rs1898830 and rs4696483 and TLR-4 rs2770150, rs1554973 and rs7856729 genotyping were performed by allelic exclusion method (real-time PCR).Result: Of the five tested TLR-2 and TLR-4 tag-SNPs, minor allele frequency of TLR-2 rs1898830 was significantly more frequent in recurrent pregnancy loss patients than in controls. Significantly higher frequencies of homozygous (2/2) TLR-2 rs1898830 (14.1% vs. 8.9%) genotype carriers were seen between recurrent pregnancy loss cases and control women. Haploview analysis identified 1-locus TLR-2 haplotype (GC) that was positively associated with recurrent pregnancy loss. No TLR-4 haplotypes associated with altered recurrent pregnancy loss risk were identified.Conclusion: These findings confirm positive associations of TLR-2 rs1898830 with recurrent pregnancy loss, further supporting a role for TLR signalling in defining pregnancy outcome.

Genetic variation in the progesterone receptor gene and susceptibility to recurrent pregnancy loss: a case-control study.

OBJECTIVE: To investigate the association of progesterone receptor (PGR) gene variants with susceptibility to recurrent pregnancy loss (RPL). DESIGN: Retrospective case-control study. SETTING: Outpatient obstetrics and gynaecology clinics. POPULATION: Women with RPL (396), defined as three or more consecutive miscarriages of unknown aetiology, and 361 women used as controls. METHODS: PGR genotyping was performed by the allelic exclusion method (real-time polymerase chain reaction). MAIN OUTCOME MEASURES: PGR single nucleotide polymorphisms (SNPs) and the distribution of their alleles, genotypes and haplotypes. RESULTS: Higher minor allele frequencies (MAFs) for rs590688, rs10895068, and rs1942836 were seen in RPL cases than in controls, which remained significant after controlling for multiple comparisons. Significantly higher frequencies of heterozygous (1/2) rs608995, along with heterozygous (1/2) and homozygous (2/2) rs590688, rs10895068, and rs1942836 genotype carriers, were seen between RPL cases versus controls, respectively, which persisted after controlling for age, body mass index (BMI), and menarche. The increased risk of RPL associated with rs590688 and rs1942836 was dependent on the number of minor alleles, thus suggesting a 'dose-dependent' effect associated with both variants. Varied linkage disequilibrium (LD) was noted between rs590688, rs10895068, rs608995, and rs1942836 PGR variants associated with RPL. Haplotypes with an increased frequency of CGTC and reduced frequency of GGAT were noted in women with RPL, compared with controls, thereby indicating these haplotypes as RPL-susceptible and RPL-protective, respectively. This association persisted after controlling for multiple comparisons, and after adjusting for covariates. CONCLUSIONS: We have confirmed a positive association of specific PGR variants (rs590688, rs10895068, and rs1942836) and PGR haplotypes (ATGCCGTC and ATTCGGTC) with an increased risk of RPL, thereby supporting a role for PGR as an RPL candidate locus. TWEETABLE ABSTRACT: Genetic variants in progesterone receptor gene are associated with increased risk of recurrent pregnancy loss.