16例无创产前检测8号染色体异常病例的产前诊断结果及妊娠结局分析

Analysis of prenatal diagnosis results and pregnancy outcomes of 16 cases with chromosome 8 abnormality detected by non-invasive prenatal testing

目的探讨无创产前检测(non-invasive prenatal testing,NIPT)提示8号染色体异常病例的产前诊断、遗传学咨询和妊娠结局。方法2016年4月1日至2022年10月31日,在中国医学科学院北京协和医院进行NIPT检测的孕妇中,结果为8号染色体异常且接受产前诊断的孕妇共16例。所有病例均接受羊膜腔穿刺术,进行羊水细胞染色体核型分析及染色体微阵列分析(chromosomal microarray analysis,CMA),部分病例进行针对8号染色体的未培养细胞的荧光原位杂交(fluorescence in situ hybridization,FISH)。回顾性分析患者的临床资料、产前遗传学诊断结果和妊娠结局。结果①13例未提示其他染色体异常,为孤立性NIPT 8号染色体异常组。其中1例为胎儿8-三体嵌合体,经咨询后继续妊娠,后续超声检查未见异常,随访新生儿未见异常。其余12例产前遗传学检测均未见异常,除3例失访之外,所有病例均继续妊娠,随访新生儿均未见异常。②3例同时提示其他染色体异常,为非孤立性NIPT 8号染色体异常组。其中1例产前诊断结果为16-三体嵌合体,超声发现胎儿心脏异常,终止妊娠。其余2例产前遗传学检测未见异常,1例在孕29周发现孕妇罹患左侧乳腺癌,行剖宫产终止妊娠,随访新生儿未见异常;另1例失访。结论对于NIPT提示8号染色体异常的病例,应进一步行产前诊断,遗传学检测的方案建议包含染色体核型分析、CMA和未培养细胞的FISH分析。对于产前诊断胎儿8-三体嵌合体的病例,应进行详细的遗传咨询,如果超声检查未见异常,一般预后良好,可以考虑继续妊娠。

Objective To explore the prenatal diagnosis,genetic counseling and pregnancy outcomes of patients with chromosome 8 abnormality detected by non-invasive prenatal testing(NIPT).Method From April 1,2016 to October 31,2022,among the pregnant women who underwent NIPT in Peking Union Medical College Hospital,16 cases underwent prenatal diagnosis for chromosome 8 abnormality.All the 16 cases underwent amniocentesis for prenatal chromosomal karyotyping and chromosomal microarray analysis(CMA).Fluorescence in situ hybridization(FISH)of uncultured cells on chromosome 8 was completed in some cases.Clinical data,prenatal genetic diagnosis results,and pregnancy outcomes were analyzed retrospectively.Result①13 cases without other chromosomal abnormality were considered as isolated NIPT chromosome 8 abnormality group(isolated group).One case was diagnosed as trisomy 8 mosaicism,and the pregnant woman decided to continue the pregnancy after counseling.No abnormality was found in prenatal ultrasound examination and postnatal neonatal follow-up.The other 12 cases were normal in the prenatal genetic testing and continued the pregnancy except three cases lost follow-up.No abnormality was found in neonates during follow-up.②Three cases with other chromosomal abnormalities were considered as non-isolated NIPT chromosome 8 abnormality group(non-isolated group).One case was diagnosed as trisomy 16 mosaicism with fetal heart abnormality by ultrasound,and the pregnancy was terminated.The other two cases were normal in the prenatal genetic testing.One pregnant woman was diagnosed as left breast cancer at 29 gestational weeks of pregnancy,who terminated the pregnancy via cesarean section,and no abnormality was found in the newborn during follow-up.One case lost follow-up.Conclusion Further prenatal diagnosis should be performed in cases with chromosome 8 abnormality detected by NIPT.The recommended genetic testing regimen includes chromosomal karyotyping,CMA and FISH analysis of uncultured cells.For cases diagnosed as trisomy 8 mosaicism,detailed genetic counseling should be performed.If no abnormality is detected by ultrasound,the prognosis of the fetus would be good in general,and the pregnancy could be considered to continue.