产前诊断中羊水染色体平衡易位的细胞遗传学分析

Cytogenetic analysis on balanced translocation of amniotic fluid chromosome during prenatal diagnosis

目的探讨羊水染色体平衡易位的产前指征分布及妊娠结局情况,为该地区的优生提供科学依据。方法对2011年2月-2015年3月在该院进行羊水染色体核型分析的76例平衡易位病例进行回顾分析。结果 76例病例的主要产前指征为高龄妊娠(38例)、夫妇易位携带者(20例)、唐氏筛查高风险(9例)、不良孕产史(5例)、B超结果异常(2例)及其他原因(2例)。17例为新发突变(14例简单易位和3例复杂重排),14例简单易位中9例选择继续妊娠,4例选择终止妊娠,1例由于涉及X-常染色体易位,B超证实存在先天畸形行终止妊娠。检出1例为易位伴随Turner综合征,1例为复杂型易位伴随缺失与重复。结论羊水染色体核型平衡易位者可由于伴随非整倍体异常、新突发X-常染色体易位及复杂易位而导致胎儿畸形。新突发简单易位需依据B超等详细结果给予准确妊娠指导。

Objective To explore the distribution of prenatal indications and pregnancy outcome among cases with balanced transloca- tion of amniotic fluid chromosome, provide a scientific basis for eugenics in the region. Methods Seventy-six cases with balanced translocation were treated by amniotie fluid chromosome karyotyping in the hospital from February 2011 to March 2015, then the data was analyzed retrospectively. Results The main prenatal indications of 76 cases were advanced maternal age （38 cases） , carriers （20 cases） , highisk Down＇s syndrome cases （9 cases） , adverse pregnancy history （5 cases） , abnormal ultrasound findings （2 cases） , and other causes （2 cases） . Seventeen cases were de novo mutation cases, including 14 simple translocation cases and 3 complex chromosome rearrangements cases. Among 14 cases with simple translocation, 9 cases continued pregnancy and 4 cases terminated pregnancy, one case with X-autosomal transloeation terminated pregnancy after diagnosed as birth defect by ultrasonography. One case was diagnosed as translocation combined with Turner syndrome, one case was diagnosed as complex chromosome rearrangements combined with deletion and duplication. Conclusion Fetal abnormalities often occur in the patients with balanced translocation of amniotic fluid chromosome because of combining aneuploid, de nnvo X-autosome translocation, and complex chromosome rearrangements. For the cases with de novo simple translocation, pregnancy should be guided according to detailed results of uhrasonography.