■染色体18p缺失综合征是由18号染色体短臂完全或部分缺失引起的疾病,关于18p缺失综合征的产前诊断报道很少。无创性产前检测(NIPT)广泛应用于常见胎儿染色体非整倍体的筛查。然而,分段删除和重复也应关注。除了一些病例增加了颈透明或全前脑,18p缺失综合征的大多数胎儿表型在怀孕期间可能并不明显,在产前检查中总是偶然发现18p缺失综合征。
■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。
UNASSIGNED: Chromosome 18p deletion syndrome is a disease caused by the complete or partial deletion of the short arm of chromosome 18, there were few cases reported about the prenatal diagnosis of 18p deletion syndrome. Noninvasive prenatal testing (NIPT) is widely used in the screening of common fetal chromosome aneuploidy. However, the segmental deletions and duplications should also be concerned. Except that some cases had increased nuchal translucency or holoprosencephaly, most of the fetal phenotype of 18p deletion syndrome may not be evident during the pregnancy, 18p deletion syndrome was always accidentally discovered during the prenatal examination.
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.