The value of karyotype analysis and copy number variation sequencing in prenatal genetic diagnosis of pregnant women with abnormal nuchal translucency values
LV Xiangkun
ZHANG Kun
JIAO Aili
Abstract：Objective To explore the value of karyotype analysis and copy number variation sequencing(CNV-seq)in the prenatal genetic diagnosis of pregnant women with abnormal nuchal translucency(NT)values in early pregnancy.Methods A total of 128 pregnant women with NT≥2.5mm who were treated in our hospital from January 2017 to December 2020 were selected as the research subjects.Amniotic fluid was extracted by amniocentesis for karyotype analysis and CNV-seq.Results A total of 22 karyotype abnormalities(17.19%)were detected in 128 fetuses with an increased NT value,including 14 cases of trisomy 21,1 case of trisomy 21 mosaicism,3 cases of sex chromosome abnormality,2 cases of trisomy 18 and 2 cases of other chromosomal abnormalities.There were 76 cases of 2.5mm≤NT<3.5mm,23 cases of 3.5mm≤NT<4.5mm and 15 cases of NT≥4.5mm.The detection rates of karyotype abnormalities were 10.53%,21.21%and 36.84%in the above three groups respectively,with a significant difference(P<0.05).Among the 128 fetuses with an increased NT value,98 cases were in the simple NT thickening group and 30 cases in the NT thickening combined with other abnormalities like serological screening abnormalities,other ultrasound abnormalities,chromosome abnormalities of the spouse,and adverse pregnancy and childbirth history.The detection rates of karyotype abnormalities in the two groups were 12.24%and 33.33%,respectively,with a significant difference(P<0.05).The CNV-seq showed suspicious or known pathogenic CNVs in 25 cases(19.53%),but balanced translocations and Roche translocations were not detected.Conclusion NT thickening is positively correlated with the risk of fetal chromosomal abnormalities.The combined use of karyotype analysis and CNV-seq can increase the detection rate of karyotypic abnormalities,effectively determine the source of karyotypic variation,and facilitate prenatal genetic counseling.
Keywords：karyotype analysiscopy number variation sequencingneck hyalineprenatal genetic diagnosischromosomal abnormalities
Publication Date：2023-12-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 3761-3763,3767 )