鼻骨发育异常胎儿产前诊断结果的分析

Application of chromosomal analysis for 29 cases of fetuses with nasal bone absence or hypoplasia

目的分析鼻骨发育异常胎儿染色体异常的类型及分布。方法回顾性分析2013年1月1日至2016年12月31日北京妇产医院共29例鼻骨发育异常胎儿临床资料，胎儿均通过经腹绒毛取样、羊膜腔穿刺或脐静脉穿刺的方法进行了染色体核型及基因拷贝数变异的分析。结果29例鼻骨发育异常胎儿中，鼻骨缺失24例，鼻骨发育不良5例；总的染色体异常发生率为51．7％（15／29），其中以21-三体居多，共8例，13-三体2例，性染色体异常2例，致病性基因拷贝数变异3例；鼻骨发育不良胎儿染色体异常比例（2／5）低于鼻骨缺失病例（13／29，54．2％）；孤立性鼻骨发育异常胎儿的染色体异常发病率（4／13）低于综合征性鼻骨发育不良的染色体异常发病比例（11／16）。结论孤立性及综合征性鼻骨发育异常均为染色体异常的重要指标，对于鼻骨发育异常胎儿的产前诊断，除了常规的核型以外，还需要重视基因拷贝数变异的检测。

Objectives To explore the chromosomal analysis for fetuses with nasal bone absence or hypoplasia. Methods This was a retrospective study on 29 pregnancies nasal bone absence or hypoplasia which underwent prenatal diagnosis, including chorionic villi （CV）, amniotic fluid or cordocentesis. The indication of the procedures and results were evaluated. Result Fifteen （51.7% , 15/29） of chromosome abnormities were diagnosed with indication of fetal nasal bone absence or hypoplasia, including eight with trisomy 21, two with trisomy 13, two with X chromosome aneuploidy and three with pathogenic copy number variations （CNVs） respectively. The incidence of chromosomal abnormalities in fetus with nasal bone hypoplasia （2/5, 40% ） was lower than that in fetus with nasal bone absence （ 13/29, 54. 2% ） . The incidence of chromosomal abnormalities in fetus with non-syndromic nasal bone absence or hypoplasia （4/ 13） was lower than that in fetus with syndromic nasal bone absence or hypoplasia （11/16）. Conclusion The incidence of chromosomal abnormalities in fetus with nasal bone absence or hypoplasia was higher and prenatal diagnosis was recommended for all types of the disease. For the fetus with nasal bone absence or hypoplasia, it is recommended to give priority to CNVs for prenatal diagnosis.