Detection of complex deletions in chromosomes 13 and 21 in a fetus by noninvasive prenatal testing

Ting Wang, Chengying Duan, Cong Shen, Jingjing Xiang, Quanze He, Jie Ding, Ping Wen, Qin Zhang, Wei Wang, Minjuan Liu, Hong Li, Haibo Li, Lili Zhang

To detect complex fetal subchromosomal abnormalities by noninvasive prenatal testing (NIPT). After routine prenatal serum screening, the plasma of high-risk pregnant women were tested via NIPT, and the NIPT results were further validated by fetal karyotype analysis and array-based comparative genomic hybridization (aCGH) through amniocentesis. In addition, the chromosome karyotypes of the parents were also analyzed. NIPT results indicated subchromosomal abnormalities in chromosomes 13 and 21; aCGH results showed 22 Mb and 16 Mb deletions in 13 q31.3 - q34 and 21q11.1 - q21.3, respectively; and the fetal karyotype was 45,XX, der(13),-21. The maternal karyotype 46,XX,inv(9)(p12q13),t(13;21)(q31.3;q21.3) was abnormal, while the paternal karyotype showed no obvious abnormality. In this study, we successfully detected complex deletions in chromosomes 13 and 21 in a fetus using NIPT, and NIPT can provide effective genetic information for the detection of fetal subchromosomal abnormalities.