The Association Study Of Chromosome Copy Number Variation And Intrauterine Bacterial Flora In Spontaneous Aborted Fetuses In Early Pregnancy

Objective: 1.To evaluate the genetic diagnostic value of CNVplex high-throughput chromosome copy number assay for spontaneous abortion in early pregnancy,and to establish an abortion histogenetic assay scheme;2.To analyze the bacterial diversity of abortion tissues and explore its relationship with spontaneous abortion;3.To explore the correlation between fetal chromosome copy number and intrauterine bacterial diversity.Methods: 1.Chromosome G-banding karyotype analysis and CNVplex chromosome copy number detection were carried out in 196 cases of spontaneous abortion,and STR technique was used to identify maternal cell contamination.2.DNA was extracted from the abortive villi of 52 patients,and the bacterial diversity was analyzed by 16 S rDNA sequencing.3.Samples were divided into two groups according to normal and abnormal chromosome copies,and the flora was analyzed and compared.Results: 1.CNVplex was successfully detected in 194 cases(98.98%)and G-banding karyotype analysis in 175 cases(89.29%).Among the 175 successful samples,10 were found to be inconsistent,including 2 polyploidy and 2 low-proportion chimerism which were not detected by CNVplex technique;1 translocation 22 trisomy and CNVplex 22 trisomy;and 5 CNVplex abnormal chromosome fragment copies.Often or not clear.There was no significant difference between the abnormal detection rate of CNVplex and the karyotype analysis,and the detection success rate and accuracy were better than the karyotype analysis,but the polyploidy and chromosome translocation could not be detected because of the limitation of technical principles.2.The main phylum of abortive villi were Proteobacteria and Firmicutes,and Enterobacteriaceae was the dominant genus.The overall diversity and abundance of the flora were low;3.The flora structure of the normal and abnormal chromosome copy groups were significantly different at 1 phylum and 18 genuses,but there was no significant difference in the overall flora composition.Conclusion: 1.The combination of traditional chromosome karyotype analysis with CNVplex and STR can provide more accurate and instructive reports for the genetic detection of abortion tissues,which is suitable for clinical application.2.The diversity and abundance of bacterial community in spontaneous abortion tissues are low,main of them are Enterobacteriaceae.3.There is a certain correlation between fetal chromosome copy number variation and intrauterine low abundance flora composition.