Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Department of Biochemistry, faculty of Medicine, Kurdistan University of Medical Sciences, Sanadaj, Iran.
Curr Mol Med. 2019;19(2):105-111. doi: 10.2174/1566524019666190226124135.
Beta thalassemia is a common disorder with autosomal recessive inheritance. The most prenatal diagnostic methods are the invasive techniques that have the risk of miscarriage. Now the non-invasive methods will be gradually alternative for these invasive techniques.
The aim of this study is to evaluate and compare the diagnostic value of two non-invasive diagnostic methods for fetal thalassemia using cell free fetal DNA (cff-DNA) and nucleated RBC (NRBC) in one sampling community.
10 ml of blood was taken in two k3EDTA tube from 32 pregnant women (mean of gestational age = 11 weeks), who themselves and their husbands had minor thalassemia. One tube was used to enrich NRBC and other was used for cff-DNA extraction. NRBCs were isolated by MACS method and immunohistochemistry; the genome of stained cells was amplified by multiple displacement amplification (MDA) procedure. These products were used as template in b-globin segments PCR. cff-DNA was extracted by THP method and 300 bp areas were recovered from the agarose gel as fetus DNA. These DNA were used as template in touch down PCR to amplify b-globin gen. The amplified b-globin segments were sequenced and the results compared with CVS resul.
The data showed that sensitivity and specificity of thalassemia diagnosis by NRBC were 100% and 92% respectively and sensitivity and specificity of thalassemia diagnosis by cff-DNA were 100% and 84% respectively.
These methods with high sensitivity can be used as screening test but due to their lower specificity than CVS, they cannot be used as diagnostic test.
β地中海贫血是一种常见的常染色体隐性遗传病。最常用的产前诊断方法是有流产风险的侵袭性技术。现在，非侵袭性方法将逐渐替代这些侵袭性技术。
本研究旨在评估和比较使用游离胎儿 DNA（cff-DNA）和有核红细胞（NRBC）在一个采样社区中的两种非侵入性诊断方法对胎儿地中海贫血的诊断价值。
从 32 名有轻微地中海贫血的孕妇（平均孕周= 11 周）中采集 2 管 K3EDTA 血，每管 10ml。一管用于富集 NRBC，另一管用于提取 cff-DNA。通过 MACS 方法和免疫组织化学法分离 NRBC；用多重置换扩增（MDA）程序扩增染色细胞的基因组。这些产物被用作 b-珠蛋白片段 PCR 的模板。用 THP 法提取 cff-DNA，从琼脂糖凝胶中回收 300bp 区域作为胎儿 DNA。这些 DNA 被用作降落 PCR 的模板，扩增 b-珠蛋白基因。对扩增的 b-珠蛋白片段进行测序，并与 CVS 结果进行比较。
数据显示，NRBC 诊断地中海贫血的敏感性和特异性分别为 100%和 92%，cff-DNA 诊断地中海贫血的敏感性和特异性分别为 100%和 84%。
这些方法具有较高的敏感性，可作为筛查试验，但由于特异性低于 CVS，不能作为诊断试验。
