title: A prenatal case with discrepant findings between non-invasive prenatal testing and fetal genetic testings.
abstract: At 17(+4) week, non-invasive prenatal testing (NIPT) results of a 24-years-old mother showed high risk of monosomy X (45, X). Abnormally shaped head and cardiac defects were observed in prenatal ultrasound scan at 19(+3) week. Amniocentesis conducted at 19(+3) week identified karyotype 47, XX, +18, which suggested that the NIPT failed to detect trisomy 18 (T18) in this case. With a further massively parallel sequencing (MPS) of maternal blood, fetal and placental tissues, we found a confined placental mosaicism (CPM) with non-mosaic T18 fetus and multiclonal placenta with high prevalence of 45, X and low level of T18 cells. FISH and SNP-array evidence from the placental tissue confirmed genetic discrepancy between the fetus and placenta. Because the primary source of the fetal cell-free DNA that NIPT assesses is mostly originated from trophoblast cells, the level of T18 placental mosaicism may cause false negative NIPT result in this rare case of double aneuploidy.
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Pan
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Baojuan
authors.initials: B
authors.lastname: Sun
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Huang
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jing
authors.affiliation: iGenomics, Guangzhou, China.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Liu
authors.affiliation: BGI-Shenzhen, Shenzhen, China.
authors.forename: Fuman
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhou
authors.affiliation: BGI-Shenzhen, Shenzhen, China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Lin
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Hongni
authors.initials: H
authors.lastname: Yue
authors.affiliation: State key Laboratory of Reproductive Medicine, Department of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital Affiliated to Nanjing Medical University, 123 Tianfei Street, Nanjing 210029, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Hu
authors.affiliation: Laboratory of Clinical Genetics, Department of Prenatal Diagnosis, Huaian Maternal and Child Health Care Hospital of Jiangsu Province, Huaian 223002, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ning
keywords: Massively parallel sequencing; Mosaicism; Non-invasive prenatal testing