Value of non-invasive prenatal testing for the detection of fetal chromosomal copy number variations / 中华医学遗传学杂志

OBJECTIVE@#To explore the value of non-invasive prenatal testing (NIPT) for the detection of fetal chromosome copy number variations (CNVs).@*METHODS@#Clinical data of 18 661 pregnant women who underwent NIPT were collected. For fetuses suspected for carrying CNVs, amniotic fluid samples were collected for chromosomal karyotyping and/or chromosomal microarray analysis (CMA).@*RESULTS@#Among all samples, NIPT suggested that 58 fetuses carried trisomy 21, 18 carried trisomy 18, 19 carried trisomy 13, 1 carried trisomies 18 and 21. Eighty eight women accepted invasive prenatal diagnosis. The results of CMA in 59 cases were consistent with those of NIPT, which yielded a consistency rate of 67.05%. In addition, 37 cases of fetal CNVs were detected by NIPT, of which 19 (15 microdeletions and 4 microduplications) have accepted invasive prenatal diagnosis. In 14 cases, the results were consistency with those of NIPT, with a consistent rate of 73.68%.@*CONCLUSION@#NIPT features high sensitivity and accuracy. Invasive prenatal diagnosis should be considered for CNVs detected by NIPT, and by tracing its parental origin, it can provide guidance for clinical practice.

Prenatal diagnosis of women with an adverse reproductive history using both traditional karyotyping and SNP-array / 中华妇产科杂志

Objective To explore the occurrence of fetal chromosomal abnormalities among pregnant women with an adverse reproductive history using traditional karyotyping and single nucleotide polymorphism microarray(SNP-array)technology.Methods Totally 94 in 2 163(4.35%)cases of singleton pregnant women with an adverse reproductive history were performed amniocentesis in Jinhua Maternal and Child Health Care Hospital from June 2015 to June 2017. Traditional karyotyping and SNP-array were employed simultaneously for prenatal diagnosis,and the detection rates of the two methods were compared. Results All of the 94 specimens were successfully analyzed, 11 cases were found with chromosomal anomaly, the overall detection rate was 11.7%(11/94). Seven (7.4%,7/94) abnormalities cases were detected by karyotyping,and 7(7.4%)by SNP-array.The karyotyping results of trisomy 21,and 45,X and the deletion of chromosome 13 were consistent with SNP-array.Only 3(3.2%,3/94)microdeletion/duplications (the sizes of duplications and deletions were between 422.4-1 708.4 kb)and 1(1/4)loss of heterozygosity were detected by SNP-array,but were missed by karyotyping.Furthermore, 2 cases′copy number variation were found pathogenic gene related, while the other 2 were considered benign or variant of uncertain significance. Four cases(4/7)of abnormalities were detected by karyotyping, while confirmed balanced translocation and inversion by SNP-array.All patients were informed and chosen to continue the pregnancy.Conclusions The rate of abnormal fetal chromosomes in pregnant women with an adverse reproductive history is still high.SNP-array is a new molecular genetic technique,and combined with use of traditional karyotyping,it could improve the detection rate of fetal chromosomal abnormalities and reduce abortion rate, thus providing a basis for genetic counseling and prenatal diagnosis.