2例地中海贫血基因无创产前(NIPT)筛查病例报告

A report of 2 cases of fetal thalassemia detected by non-invasive prenatal screening

目的探索母体血浆无创产前(NIPT)筛查地中海贫血的临床实践,减少地贫的漏诊及误诊率,防止重型地贫患儿的出生。方法回顾性分析2021年5—6月在本院确诊的2例地中海贫血患儿的产前诊断结果和妊娠结局,其中产前诊断均进行了NIPT检测和PCR-反向点杂交方法检测主要的地中海贫血基因。结果NIPT检测结果显示,1号胎儿血红蛋白基因为-α^(3.7)/--^(SEA)复合杂合缺失突变,2号胎儿基因为--^(SEA)/--^(SEA)纯合缺失突变,均具有患地中海贫血症风险。经过羊水地贫基因检测并进一步与这2例胎儿父母基因型结果比对表明,1号胎儿的-α^(3.7)缺失突变来源于父亲,其--^(SEA)缺失突变来源于母亲。该父母决定完成妊娠,出生后抽取1号患儿血浆,经检测显示,该患儿基因型与NIPT检测结果和羊水检测结果一致;2号胎儿经过羊水地贫基因检测,证实为--^(SEA)/--^(SEA)纯合缺失突变,分别来自其携带者父母,该胎儿父母决定引产。结论本研究的两例地中海贫血胎儿均通过母体血浆无创地贫筛查准确检出,并经羊水检测确诊,有效的防止了重型地贫儿的出生。

Objective To explore the clinical practice of noninvasive prenatal testing(NIPT)in scanning of thalassemia,reduce the missed diagnosis and misdiagnosis ratios of thalassaemia,and prevent the birth of children with severe thalassaemia diseases.Methods The prenatal diagnosis results and pregnancy outcomes of 2 fetuses with thalassemia diagnosed in our hospital from May 2021 to June 2021 were retrospectively analyzed.Results NIPT results showed that the hemoglobin genotype of No.1 fetus was-α^(3.7)/--^(SEA) compound heterozygous deletion mutation,and the genotype of No.2 fetus was--^(SEA)/--^(SEA) homozygous deletion mutation.Both of them had the risk of thalassemia.Amniotic fluid diagnosis tests were performed and their hemoglobin genotypes were further compared with genotypes of their parents.The-α^(3.7) deletion mutation of the No.1 fetus was inherited from the father,and the--^(SEA) deletion mutation was inherited from the mother.The parents decided to complete the pregnancy.After birth,hemoglobin genotype of the No.1 child was confirmed by using blood sample and the results were consistent with the NIPT results and the amniotic fluid test results.Amniotic fluid diagnosis confirmed the--^(SEA)/--^(SEA) homozygous deletion mutation of the No.2 fetus and both of the parents are--^(SEA) carriers.After diagnosis,the parents decided to terminate pregnancy.Conclusions Both two cases of thalassemia were successfully detected by NIPT and confirmed by amniotic fluid diagnosis,which prevented the birth of children with severe forms of thalassemia.