Objective: To assess the clinical application of single nucleotide polymorphism microarray (SNP array) in prenatal genetic diagnosis for fetuses with absent nasal bone.
Methods: Seventy four fetuses with absent nasal bone detected by prenatal ultrasound scanning were recruited from Women's Hospital, Zhejiang University School of Medicine during June 2015 and October 2018. The chromosome karyotypes analysis and SNP array were performed. The correlation between absent fetal nasal bone and chromosome copy number variants was analyzed.
Results: Among 74 fetuses, 19 were detected to have chromosomal abnormalities, including 16 cases of trisomy-21, 1 case of trisomy-18 and two cases of micro-deletion/duplication. Among 46 cases with isolated absence of nasal bone, 3 had trisomy-21, and 1 had a micro-duplication. Absence of nasal bone in association with nuchal translucency thickening had a higher rate of abnormal karyotypes compared with isolated absence of nasal bone (χ2=32.27,P<0.01).
Conclusions: Fetuses with absent nasal bone and nuchal translucency thickening are likely to have chromosome abnormalities, and SNP array testing is recommended to exclude the chromosome abnormalities.
目的: 评估单核苷酸多态性微阵列分析在胎儿鼻骨缺失遗传学产前诊断中的效用。
方法: 以2015年6月至2018年10月在浙江大学医学院附属妇产科医院因鼻骨缺失行染色体核型及单核苷酸多态性微阵列分析的74例孕妇为研究对象，分析胎儿鼻骨缺失及是否合并其他超声检查异常与染色体拷贝数异常的关系。
结果: 74例鼻骨缺失的胎儿中共检出染色体异常19例，其中21三体综合征16例，18三体综合征1例，染色体微重复/缺失2例。在46例不合并其他超声检查异常的单纯鼻骨缺失的病例中，21三体综合征3例，染色体微缺失1例。鼻骨缺失合并颈项透明层增厚的胎儿染色体异常的比例高于仅鼻骨缺失组胎儿（ χ 2=32.27， P < 0.01）。
结论: 胎儿鼻骨缺失合并颈项透明层增厚增加染色体异常的风险，应进一步行染色体核型及单核苷酸多态性微阵列分析以排除染色体异常的可能。