No association between apolipoprotein E polymorphisms and recurrent pregnancy loss

Problem Numerous lines of evidence implicate Apolipoprotein E (Apo E) in lipid metabolism during pregnancy. Hence, a role for its polymorphism has been envisaged in recurrent pregnancy loss (RPL) considering major structural and functional differences between different Apo E genotypes. Method of study A case control study of 81 women with two or more pregnancy losses that did not have any other known risk factors including anatomic anomalies of the reproductive system, infections, immunologic factors, hormonal imbalances, chromosomal abnormalities and environmental factors was carried out. The control group consisted of 81 women with at least two healthy children and no RPL in their reproductive history. DNA was extracted from the peripheral blood following written consent and Apo E genotyping was carried out by amplifying exon 4 of the gene and subjecting it to digestion by HhaI restriction enzyme. Results Genotyping was concluded by analyzing different fragment sizes produced, which resulted in finding significantly higher frequency of combined E3/E4 and E4/E4 genotypes in the patients (about 20 %) compared to the normal controls (2.4 %). The genotypes were confirmed by DNA sequencing. Conclusion Allelic frequency for E4 was 13.5 % in the patients and only 1 % in the non-RPL group. Our findings confirm and are in line with a number of similar studies carried out on other populations. Therefore, Apo E4 polymorphism seems to be contributing to the thrombophilic risk factors as a background to RPL.

Section: Discussionsupporting

confidence: 66%

Positive association of Apolipoprotein E4 polymorphism with recurrent pregnancy loss in Iranian patients

Asgari

Akbari

Zare

et al. 2013

“…Therefore, some studies [2,16,17] have shown that the Apo E gene could be one of the risk factors for RPL, especially the high frequency of the Apo E4 genotype. Nevertheless, some other studies [1,[18][19][20] presented no significant association of Apo E polymorphisms with recurrent pregnancy loss. On the basis of this controversy, this meta-analysis was conducted with data published in recent years.…”

Section: Diseasementioning

confidence: 86%

“…The apolipoprotein E (Apo E) gene consists of four exons and three introns, with 3597 base pairs, and is located on chromosome 19q13.2 in humans [1]. Combined with ApoC1 and C2, Apo E plays a role in cholesterol-triglyceride metabolism by producing a 299-amino acid long polypeptide in the liver and brain [2][3][4].…”

Section: Description Of Apo E Genementioning

confidence: 99%

See 1 more Smart Citation

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

Chen

et al. 2013

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.

“…The E4 allele is also involved in inflammatory response, platelet function, apoptosis, and the modulation of oxidative stress [15]. However, Bianca et al [16] concluded that no association exists between ApoE polymorphisms and recurrent pregnancy loss. The possible reason for the inconsistency is that Bianca et al compared their results in women with recurrent pregnancy loss with those in women with a history of cardiovascular disease and in women with a family history of inherited thrombophilia.…”

Section: Discussionmentioning

confidence: 99%

Association between apolipoprotein E gene polymorphism and the risk of recurrent pregnancy loss: A meta-analysis

Meng

Mei

Yuan-yuan

et al. 2013

Purpose The association between apolipoprotein E (ApoE) gene polymorphism and the risk of recurrent pregnancy loss (RPL) remains controversial. The present meta-analysis was performed to derive a precise estimate of the relationship. Method(s) We searched the PubMed, Embase, and Web of Science data-bases for studies related to the association between the ApoE genotype and the risk of RPL. We estimated the summary odds ratio (OR) with 95% confidence interval (CI) to assess the association. Result(s) Seven studies, including 2,090 RPL cases and 742 control samples, were identified. The results showed a significant association between ApoE E4 mutation and RPL risk (for E4 allele: OR =1.98, 95 %CI =1.14-3.43, P=0.499; for E2E3 vs. E3E3: OR =1.33, 95%CI =1.12-1.42, P=0.008; for E2E4 vs. E3E3: OR =1.26, 95 % CI =1.07-1.49, P=0.005). Conclusion(s)The meta-analysis suggests an association between ApoE E4 mutation and increased risk of RPL.