OBJECTIVETo assess the association of coagulation factor V gene polymorphisms with unexplained recurrent spontaneous abortion (URSA) among ethnic Han Chinese from Wenzhou area.

METHODSNinety-six patients with URSA and 103 females with a history of normal pregnancy were recruited. Genotypes of coagulation factor V gene were determined through target sequence capture and high-throughput sequencing. The results were confirmed with a MassARRAY system. Allelic and genotypic frequencies between the two groups were compared.

RESULTSNineteen single nucleotide polymorphism (SNPs), except coagulation factor V Leiden, were identified in the two groups. The frequencies of rs9287090 allele A, rs1046712 allele T and rs1800594 allele G of the URSA group were lower than those of the control group (6.77% vs. 16.50%, 3.12% vs. 13.11%, 10.94% vs. 18.45%, respectively). After Bonferroni and false discovery rate correction, rs9287090 and rs1046712 were significantly associated with URSA (corrected P<0.05). Although genotypic distribution of rs9287090 and rs1046712 also differed between the two groups, the corrected P value showed no significance (corrected P>0.05). A complete linkage disequilibrium (r=1, D'=1) of rs6022 and rs6029 was observed for the haplotype block rs6022-rs6029-rs6028. The frequencies of rs6022 allele A and rs6029 allele T were higher in the URSA group with corrected insignificance (75.00% vs. 65.53%, corrected P>0.05). Furthermore, significantly more A-T-T haplotype was found in the URSA group (75.00% vs. 65.50%, OR=1.578, 95%CI:1.021-2.438, χ=4.248, P<0.05).

CONCLUSIONThe decreased rate of rs9287090 allele A, rs1046712 allele T, and rs1800594 allele G may contribute to the susceptibility to URSA among ethnic Han Chinese from Wenzhou area. The rs6022 allele A and rs6029 allele T may also predispose to URSA.