UNASSIGNED: In our case, we found a pure partial monosomy 18p deletion during the confirmation of the result of NIPT by copy number variation sequencing (CNV-Seq). The result of NIPT suggested that there was a partial or complete deletion of X chromosome. The amniotic fluid karyotype was normal, but result of CNV-Seq indicated a 7.56 Mb deletion on the short arm of chromosome 18 but not in the couple, which means the deletion was de novo deletion. Finally, the parents chose to terminate the pregnancy.
UNASSIGNED: To our knowledge, this is the first case of prenatal diagnosis of 18p deletion syndrome following NIPT.NIPT combined with ultrasound may be a relatively efficient method to screen chromosome microdeletions especially for the 18p deletion syndrome.
■在我们的例子中,在通过拷贝数变异测序(CNV-Seq)确认NIPT结果的过程中,我们发现了纯的部分单体18p缺失。NIPT结果提示X染色体部分或完全缺失。羊水核型正常,但CNV-Seq的结果表明,在18号染色体的短臂上有7.56Mb缺失,但在夫妇中没有,这意味着删除是从头删除。最后,父母选择终止妊娠。
■据我们所知,这是NIPT后产前诊断18p缺失综合征的首例。NIPT结合超声可能是一种相对有效的方法来筛查染色体微缺失,尤其是对于18p缺失综合征。