title: Maternal mosaicism of sex chromosome causes discordant sex chromosomal aneuploidies associated with noninvasive prenatal testing.
abstract: OBJECTIVE
  To investigate the clinical efficiency of noninvasive prenatal test (NIPT) identifying fetal chromosomal aneuploidies.
  
  
  METHODS
  In the present study, 917 women with high-risk pregnancies were invited to participate in an NIPT trial based on an Illumina HiSeq massively parallel sequencing platform. Abnormal cases in NIPT were validated by karyotyping and fluorescence in situ hybridization (FISH) analysis. All of the participants' infants were examined clinically and followed up for at least 6 months.
  
  
  RESULTS
  A total of 35 (3.82%) high-risk pregnancies were detected with abnormal results in NIPT, which included 25 cases (2.73%) of trisomy 21 (Tri21), four cases (0.44%) of trisomy 18 (Tri18), four cases (0.44%) of Turner syndrome (45, X), one cases (0.11%) of Klinefelter's syndrome (47, XXY), and one cases (0.11%) with lower X chromosome concentration. Further validation indicated that one case of Tri18 and the case with lower X chromosome concentration were false positive results (0.22%) in NIPT. Furthermore, it was found that the false positive case with lower X chromosome concentration in NIPT was caused by maternal sex chromosomal mosaicism (45, X and 46, XX).
  
  
  CONCLUSIONS
  Our findings indicated that maternal mosaicism of sex chromosome could cause discordant sex chromosomal aneuploidies associated with NIPT. We highly recommended that maternal karyotype should be confirmed for the cases with abnormal results in NIPT.
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Leilei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Tang
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Yin
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Jinglu
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Shuting
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Xuyun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Haiqian
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China.
authors.forename: Qingxi
authors.initials: Q
authors.lastname: Shi
authors.affiliation: Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.
authors.forename: Edmund C
authors.initials: EC
authors.lastname: Jenkins
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China; Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.
authors.forename: Nanbert
authors.initials: N
authors.lastname: Zhong
authors.affiliation: Department of Prenatal Diagnosis, Lianyungang Maternal and Child Health Hospital, Lianyungang, Jiangsu 222001, China. Electronic address: yinggulyg@hotmail.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Gu
mesh_terms: D000293:Adolescent; D000328:Adult; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D041321:Chromosomes, Human, X; D004314:Down Syndrome / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008875:Middle Aged; D009030:Mosaicism; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D017422:Sequence Analysis, DNA; D012729:Sex Chromosome Aberrations; D012730:Sex Chromosomes / Q000235:genetics*; D055815:Young Adult
keywords: chromosomal aneuploidies; confined placental mosaicism; maternal mosaicism; noninvasive prenatal test; prenatal diagnosis