PDF(Pubmed)
Abstract：
Chromosomal rearrangements can interfere with the disjunction and segregation of other chromosome pairs not involved in the rearrangements, promoting the occurrence of numerical abnormalities in resulting gametes and predisposition to trisomy in offspring. This phenomenon of interference is known as the interchromosomal effect (ICE). Here we report a prenatal case potentially generated by ICE. The first-trimester screening ultrasound of the pregnant woman was normal, but the NIPT indicated a high risk for three copies of chromosome 21, thus suspecting trisomy 21 (T21). After a comprehensive clinical evaluation and genetic counseling, the couple decided to undergo amniocentesis. The prenatal karyotype confirmed T21 but also showed a balanced translocation between the long arm of chromosome 15 (q22) and the long arm of chromosome 22. The parents\' karyotypes also showed that the mother had the 15;22 translocation. We reviewed T21 screening methods, and we performed a literature review on ICE, a generally overlooked phenomenon. We observed that ours is the first report of a prenatal case potentially due to ICE derived from the mother. The recurrence risk of aneuploidy in the offspring of translocated individuals is likely slightly increased, but it is not possible to estimate to what extent. In addition to supporting observations, there are still open questions such as, how frequent is ICE? How much is the aneuploidy risk altered by ICE?
摘要：
染色体重排可干扰不参与重排的其他染色体对的分离和分离。促进产生的配子中数字异常的发生和后代三体性的倾向。这种干扰现象被称为染色体间效应(ICE)。在这里，我们报告了一个可能由ICE产生的产前病例。孕妇的孕早期超声检查是正常的,但是NIPT表明21号染色体三拷贝的风险很高，因此怀疑21三体（T21）。经过全面的临床评估和遗传咨询，这对夫妇决定进行羊膜穿刺术。产前核型证实了T21，但也显示了15号染色体长臂（q22）和22号染色体长臂之间的平衡易位。父母的核型也显示母亲有15;22易位。我们回顾了T21筛查方法，我们对ICE进行了文献综述，一个普遍被忽视的现象。我们观察到，我们的报告是可能由于来自母亲的ICE引起的产前病例的第一份报告。易位个体后代非整倍体的复发风险可能略有增加，但是无法估计到什么程度。除了支持观察，仍然有一些悬而未决的问题，例如，ICE改变了多少非整倍性风险？
