一例表现为颈项透明层增厚的2p15-16.1微缺失胎儿的产前诊断及遗传学分析

摘要

We reported the prenatal molecular diagnosis and pregnant outcome of a fetus with increased nuchal translucency.The ultrasound findings of the gravida at 12+5 gestational weeks indicated that the fetal nuchal translucency thickness was 4.5 mm,and non-invasive prenatal testing suggested as low risk.Amniocentesis was performed at 18 gestational weeks.Fetal chromosomal karyotype was normal but chromosome microarray comparative genomic hybridization analysis identified a 1.878 Mb deletion on chromosome 2p15-16.1.No copy number variation was found in the parents.The microdeletion was also verified by multiplex ligation-dependent probe amplification.Literature reported that chromosome 2p 15-16.1 microdeletion syndrome was characterized by mental retardation,language developmental disorder,microcephaly and so on.This case we reported here was a de novo 2p 15-16.1 microdeletion which contained the critical region and genes of 2p 15-16.1 microdeletion syndrome and was inferred to be a pathogenetic mutation.The gravida chose to terminate the pregnancy after genetic consultation.%本文报道一例颈项透明层增厚胎儿的产前分子诊断过程及妊娠结局.孕妇孕12周+5超声检查提示胎儿颈项透明层厚度4.5 mm,无创产前检测提示低风险,孕1 8周时行羊膜腔穿刺术染色体核型分析及染色体微阵列分析.染色体核型分析未见异常,染色体微阵列比较基因组杂交结果提示胎儿2号染色体p15-16.1区域存在1.878 Mb的缺失,父母检测结果未见异常.同时利用多重链接探针扩增技术证实存在缺失.文献报道2p15-16.1微缺失综合征患儿多数表现为智力低下、语言发育障碍、小头畸型等,本例胎儿2号染色体缺失区域包含2p15-16.1微缺失综合征关键区域和关键基因,且胎儿2p15-16.1微缺失为新发突变,充分告知遗传学风险后孕妇选择终止妊娠.