摘要
目的探讨NIPT三体高风险病例中出现胎儿UPD和胎盘CPM的原因及胎儿UPD的临床表现和诊断思路。方法选择因NIPT三体高风险选择介入性产前诊断,羊水核型正常而SNP array芯片分析提示杂合性缺失的3例孕妇,在胎儿出生后同时取胎盘组织和母血进行高通量DNA测序分析。结果3例单亲二体分别为4号染色体的q28.3q32.3出现大片段纯合子、13号染色体q11q12.11和q31.3q34出现大片段纯合子、16号染色体多个区域出现大片段纯合子,核型分析结果均为正常。3例胎盘验证结果均为相应染色体的限制性胎盘嵌合。结论减数分裂不分离和"三体自救"是三体高风险病例出现胎儿UPD、CPM和NIPT假阳性的原因。UPD可能对胎儿预后产生不良影响。NIPT提示三体高风险,应警惕胎儿UPD和胎盘CPM的可能性,建议选择核型分析加SNP array analysis芯片检测方法进行产前诊断。
Objective:To explore the causes of fetal UPD and placental CPM in NIPT trisomy high-risk cases,as well as the clinical manifestation and diagnosis of fetal UPD.Methods:Three pregnant women who were selected for interventional prenatal diagnosis due to the high risk of NIPT trisomy,amniotic fluid karyotype was normal,and SNP array microarray analysis suggested that they had uniparental disomy.After birth,both placental tissues and maternal blood were taken for r next generation sequencing DNA sequencing.Results:In the 3 cases,large fragment homozygotes were found in q28.3 q32.3 of chromosome 4,large fragment homozygotes in q11 q12.11 and q31.3 q34 of chromosome 13,and large fragment homozygotes in multiple regions of chromosome 16,respectively.The karyotype analysis results were all normal.The results of placental verification in 3 cases were all confined placental mosaicism with corresponding chromosomes.Conclusion:Meiotic nondissociation and"trisomy rescue"are the reasons for fetal uniparental disomy,confined placental mosaicism and NIPT false positive in pregnant women at high risk of NIPT trisomy.UPD may have adverse effects on fetal prognosis.NIPT suggests that the trisomy is high risk,the possibility of fetal UPD and placental CPM should be guarded,and it is suggested to choose the method of karyotype analysis and SNP array analysis chip for prenatal diagnosis.
作者
谢润桂
娄季武
何怡
XIE Run-gui;LOU Ji-wu;HE Yi(Center of Prenatal Diagnosis,Dongguan Maternal and Child Health Hospital,Dongguan,Guangdong,523107,China)
出处
《中国优生与遗传杂志》
2020年第4期403-407,共5页
Chinese Journal of Birth Health & Heredity
基金
东莞市社会发展科技项目(201950715007212,2018507150071536)
关键词
无创产前检测
单亲二倍体
单核苷酸多态性
原因
Noninvasive prenatal testing
Uniparental disomy
Single nucleotide polymorphisms
Causes
