Genetic testing of chorionic villi from abortuses during early pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To explore the prevalence and characteristics of chromosomal abnormalities in abortuses during early pregnancy with single nucleotide polymorphism microarray (SNP-array).@*METHODS@#For 520 abortuses, copy number variations (CNVs) in chorionic villi were analyzed with SNP-array.@*RESULTS@#In 510 (98.1%) of the samples, the analysis was successful. Among these, 57.6% (294/510) of the samples were found to harbor clinically significant chromosomal abnormalities. 38.8% of the samples (198/510) had a normal result. 2.4% (12/510) of the samples harbored benign CNVs, and 1.2% (6/510) harbored variants of uncertain significance (VOUS). Aneuploidies, polyploidies, pathogenic CNVs and uniparental disomies (UPD) had accounted for 75.2% (221/294), 13.9% (41/294), 8.2% (24/294), and 2.7% (8/294) of the samples, respectively. 45,XO was the most common finding, which was followed by trisomy 16 and trisomy 22. 69,XXY was the most common polyploidy.@*CONCLUSION@#Chromosomal abnormalities are the main cause for early miscarriage, among which aneuploidies are most common. The prevalence of aneuploidies is significantly increased among women over 35. SNP-array analysis has the advantage of high success rate, high resolution and great accuracy, but the clinical significance of microdeletions/microduplications found by SNP-array can be difficult for interpretation.

Analysis of non-invasive prenatal screening detection in fetal chromosome aneuploidy / 中华妇产科杂志

Objective To evaluate the efficacy of non-invasive prenatal screening (NIPS) in the detection of fetal aneuploidies.Methods Cell free DNA was sequenced in 5 566 pregnant women to identify the fetal aneuploidies in the First Affiliated Hospital of Zhengzhou University from January 1st,2015 to March 15th,2016.Among them,5 230 (93.96％,5 230/5 566) were singleton pregnancies and 336 (6.04％,336/5 566) were twin pregnancies.In singleton pregnancies,1 809 (34.59％,1 809/5 230) were women with advanced maternal age,and 3 421 (65.41％,3 421/5 230) were young women.The positive results of NIPS were validated by karyotyping through invasive procedures and neonatal outcomes were followed up by telephone.Results Among the 5 566 women,69 (1.24％,69/5 566) got positive NIPS results,with 66 in singleton pregnancies and 3 in twin pregnancies.Two were monochorionic diamniotic twins and 1 was dichorionic twin pregnancy.The positive predictive value of NIPS for trisomy 21,18 and 13 were 100.0％,90.9％ and 100.0％,and was 55.6％ for sex chromosome aneuploidies.There was no false negative case found during the follow-up.In the advanced maternal age group and young women group,the prevalence rates of fetal chromosomal aneuploidies were 1.11％ (20/1 809) and 0.94％ (32/3 421),respectively.In the young women with soft markers in fetal ultrasound,the prevalence of fetal chromosomal aneuploidies was 1.44％ (7/487),and in serum high risk women,it was 0.94％ (7/747).In women with the serum screening risk with cut-off value,0.89％(9/1 016) had fetal aneuploidies,and the prevalence was 0.77％(9/1 171) in volunteers.There was no statistically significant difference among these groups (P=0.636).Conclusions There is no difference in the detection rate of fetal aneuploidies between high-risk women in serum screening and volunteers in NIPS.NIPS is more suitable as a first line screening test for women without fetal ultrasound abnormalities.It should be used carefully when there is ultrasound abnormalities.