The frequency of early, spontaneous miscarriage associated with the leu33pro polymorphism of Glycoprotein IIIa: A pilot study

Comparison of two groups for the apolipoprotein E polymorphisms by using next generation sequencing: The first group with three consecutive abortions and the second group with at most one abortion in three consecutive pregnancies

The importance of apolipoprotein E genotypes and allelic polymorphisms in the etiology of recurrent miscarriage is controversial. We plan to investigate this in a two-group study involving more than a thousand participants. In total, 1046 subjects (802 participants in the first group, 244 participants in the second group) were investigated. Women in the first group had a history of ≥3 consecutive spontaneous miscarriage and women in the second group had at most one miscarriage in three consecutive pregnancies. The participants with the following evidence and symptoms were excluded from both groups; structural uterine abnormality, chrosomal abnormalities and polymorphisms, hormonal imbalance, anti-nuclear antibodies, anti-phospholipid antibodies, lupus anticoagulant and homozygous genotype for FV-Leiden, MTHFR C677T, MTHFR A1298C, prothrombin 20210G>A and plasminogen activator inhibitor 4G/5G polymorphisms. We found similar apolipoprotein E allelic frequencies and genotype distributions in both groups. The frequencies of ε2 alleles were 4.1% in the first group and 2.9% in the second group, whereas those of ε3 alleles were 90.8% and 93% in the first group and the second group, respectively and ε4 alleles were 5.1% in the first group and 4.1% in the second group. The genotypes of Apo E observed in the first and the second group respectively were as follows; ε2/ε3 (7.5% and 5.7%), ε3/ε3 (82.7% and 86.5%), ε3/ε4 (8.7% and 7.4%), ε4/ε4 (0.5% and 0.4%) and ε2/ε4 (0.6% and 0). Our data did not support a possible association between apolipoprotein E genotypes and allelic frequencies, and recurrent miscarriages. We believe that the studies excluding the etiological factors that were previously found to be related with any condition are more valuable in the scope of showing the cause-effect relationship.

Genetic heterogeneity of platelet glycoproteins Ia and IIIa is associated with in vitro fertilisation implantation failure

Thrombophilic genetic factors have been shown to play an important role in implantation outcome after in vitro fertilisation (IVF). In this pilot study we investigated the frequencies of glycoprotein Ia (GpIa)-C807T and GpIIIa-PlA1/PlA2 polymorphisms in 60 nulligravidae women with a history of unexplained IVF implantation failures and compared them with 60 healthy fertile women. We found statistically significant associations between the GpIa-C807T and GpIIIa-PlA1/PlA2 polymorphisms and IVF implantation failure (odds ratio [OR] = 3.45, 95% confidence interval [CI]: 1.63-7.30, p = 0.001; and OR = 2.86, 95% CI: 1.27-6.45, p = 0.010, respectively) with the risk being higher for combined carriers of GpIa-807T and GpIIIa-PlA2 alleles (OR = 10.13, 95% CI: 2.85-35.99, p < 0.001), suggesting a synergistic effect of the two polymorphisms. The above associations were strongest for the youngest age group. Our results indicate that GpIa-807T and GpIIIa-PlA2 may be susceptibility alleles for IVF implantation failure.

Apolipoprotein E (Apo E) gene polymorphisms and recurrent pregnancy loss: a meta-analysis

BACKGROUND

Recently, a relationship between recurrent pregnancy loss (RPL) and Apolipoprotein E (Apo E) gene polymorphisms has been proposed. In order to investigate the real association between Apo E polymorphisms and RPL, our meta-analysis was carried out.

METHODS

We estimated the association with RPL risk under dominant and recessive models, in combination with the OR and RR with a 95% confidence interval (CI), which was used to assess the association between RPL and Apo E polymorphisms.

RESULTS

According to our criterion, there were 6 studies included. The dominant model used the E4/E3 group and the OR was 1.919 (95 %CI: 1.016-3.625, I(2) = 53.8%), the RR was 1.308 (95%Cl: 1.071-1.598) suggesting that carriers of the E4 allele would have a higher risk of causing spontaneous miscarriages. In addition, the OR was 0.727 (95%CI: 0.566-0.932, I(2) = 0.0%) and RR was 0.923 (95%CI: 0.867-0.982) in a fixed model for E3/E3 homozygotes versus other genotypes, suggesting that the Apo E3 polymorphism could be a protective factor. The OR was 1.365 (95% CI: 1.029-1.811, I(2) = 0 .0%) in a fixed model comparing the E2 allele with the E3 allele, suggesting that Apo E2 polymorphisms may contribute to RPL as a risk factor. Furthermore, after conducting sensitivity analysis in the E4/E3 group, the results showed this to be consistent and the OR was 2.249 (95%CI: 1.474-3.431).

CONCLUSIONS

There is a close association between RPL and Apo E gene polymorphisms. For RPL, the Apo E4 polymorphism could be a risk factor, the Apo E3 polymorphism may be a protective factor and the Apo E2 polymorphism may be another potential risk factor.