The effects of DICER1 and DROSHA polymorphisms on susceptibility to recurrent spontaneous abortion

BACKGROUND: Recurrent spontaneous abortion (RSA) is a serious problem in pregnancy. The exact etiology of RSA is unknown in more than 50% of all the patients. However, genetic variations are known as susceptibility factors for idiopathic RSA. Considering the role of miRNA biosynthesis machinery in the miRNA production and effect of miRNAs on various diseases, this study aimed to evaluate the effects of DICER1 rs3742330 and DROSHA rs6877842 polymorphisms on RSA risk. METHODS: In this case-control study, 150 RSA patients and 195 age-matched healthy female controls were recruited. Both polymorphisms were genotyped using PCR-RFLP method. RESULTS: The frequency of DICER1 rs3742330AG genotype was higher in the control group (P = .022). There was a statistically significant association between rs3742330 polymorphism and a reduced RSA risk in dominant and allelic models (P = .013 and P = .007, respectively). No statistically significant association was found between DROSHA rs6877842 variant and RSA risk. The combination of AG and GC genotypes and G-G alleles of DICER1 rs3742330 and DROSHA rs6877842 polymorphisms led to a decreased RSA risk. However, the synergic effect of rs3742330A and rs6877842G alleles (A-G) and AA-GG genotypes was associated with an increased RSA risk. CONCLUSION: the DICER1 rs3742330AG genotype and combination of AG and GC genotypes and G-G alleles of DICER1 rs3742330 and DROSHA rs6877842 polymorphisms were associated with a reduced RSA risk.