PRENATAL DIAGNOSIS OF INHERITED BLOOD DISORDERS

在怀孕期间，少量胎儿红细胞进入母体 流通 在这些细胞中，有核红细胞被称为 正常成纤维细胞 使用特异性探针对这些正常成红细胞进行基因组分析 通过原位杂交或聚合酶链反应（PCR） 潜在地提供了一种非侵入性的方法，用于诊断遗传性 缺陷 因为母体细胞中胎儿正常成红细胞的数量 是非常低的，需要一系列的浓缩步骤，以获得 胎儿细胞的同质群体。 我们已经开发出了 使用流式细胞术方法获得胎儿正常成红细胞。 我们有 还确定了对由以下制备的基因组DNA进行PCR的条件： 只有50个细胞 该提案的目标是：1）设计 从胎儿中分离纯的胎儿正常成红细胞群的技术 少量母体血液样本和2）使用来自 少量的母血样本和2）使用富集的正常母细胞 用于检测单拷贝基因的群体。 污染控制 母亲的基因组DNA将被纳入研究的基础上，高度 包括“TG”重复序列的多态性重复序列， 发现于人类7号染色体上。 第二阶段将侧重于产前 诊断特定的遗传性疾病，例如镰状细胞贫血和 地中海贫血 建议的商业应用：我们打算设计一种非侵入性的 遗传缺陷的产前诊断方法。 除了 降低对胎儿的风险，我们的采样方法有可能 在商业诊断实验室中自动处理样品。

During pregnancy small numbers of fetal erythrocytes enter the maternal circulation. Among these cells are nucleated erythrocytes called normoblasts. Genomic analysis of these normoblasts using specific probes by in situ hybridization or the polymerase chain reaction (PCR) potentially provides a non-invasive method for diagnosis of genetic defects. Because the number of fetal normoblasts among the maternal cells is extremely low, a series of encrichment steps is required to obtain a homogeneous population of fetal cells. We have developed methods for obtaining fetal normoblasts using a flow cytometric approach. We have also determined conditions for performing PCR on genomic DNA prepared from as little as 50 cells. The goals of this proposal are: 1) to devise techniques for isolating a pure population of fetal normoblasts from a small sample of maternal blood and 2) to use the enriched normoblast from a small sample of maternal blood and 2) to use the enriched normoblast population for detecting single copy genes. Controls for contaminating maternal genomic DNA will be incorporated into the study based on highly polymorphic repeat sequences including a "TG" repeat sequence we discovered on human chromosome 7. Phase II will focus on prenatal diagnosis of specific genetic disorders such as sickle cell anaemia and thalassaemia. PROPOSED COMMERCIAL APPLICATION: We intend to devise a non-invasive method for prenatal diagnosis of genetics defects. In addition to reducing the risk to the fetus, our sampling method has the potential for automated processing of samples in a commercial diagnostic laboratory.