He X, Zhu D, Han Z, Liu X, Wang G, Chu S, Zhang W, Zhou H, Mao S, Zhuang Q, Zhao Y, Huang W
Ruijin Hospital, Shanghai Second Medical University, Shanghai Institute of Hypertension, Shanghai, 200025 P. R. China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2001 Dec;18(6):421-5.
To diagnose zygosity of twins by microsatellite polymorphism.
One hundred and eighty-four samples, including 69 pairs of twins with the same gender and 6 pairs of twins with different gender were recruited. Seventeen sib pairs were also collected for controls. Nine highly polymorphic microsatellite loci were amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers and the products were sized by automated fragment analysis after electrophoresis and laser detection. Zygosity was diagnosed by comparing the concordance of the genotype of the 9 markers.
Sixty-three pairs of monozygotic (MZ) and 12 pairs of dizygotic (DZ) twins were assigned their zygosity by comparison of polymorphism of 9 microsatellite loci. Within each of the 63 monozygotic (MZ) pairs there was complete concordance. However, within each of the 12 dizygotic pairs and other 17 sib pairs, discordant loci were found. With five or six markers, the probability that any twin pair was MZ if all markers were concordant was 99% or 99.6%, respectively. With all the nine markers, the probability that any twin pair was MZ if all markers were concordant was 99.95%.
The technology of gene scan and genotyping provides a rapid and reliable approach to zygosity detection.
通过微卫星多态性诊断双胞胎的合子类型。
招募了184份样本，包括69对同性双胞胎和6对异性双胞胎。还收集了17对同胞对作为对照。使用荧光标记引物通过聚合酶链反应（PCR）扩增9个高度多态性微卫星位点，电泳和激光检测后通过自动片段分析对产物进行大小测定。通过比较9个标记的基因型一致性来诊断合子类型。
通过比较9个微卫星位点的多态性，确定了63对同卵（MZ）双胞胎和12对异卵（DZ）双胞胎的合子类型。在63对同卵（MZ）双胞胎中，每对双胞胎的基因型完全一致。然而，在12对异卵双胞胎和其他17对同胞对中，均发现了不一致的位点。如果所有标记均一致，使用5个或6个标记时，任何一对双胞胎为同卵双胞胎的概率分别为99%或99.6%。使用全部9个标记时，如果所有标记均一致，任何一对双胞胎为同卵双胞胎的概率为99.95%。
基因扫描和基因分型技术为合子类型检测提供了一种快速可靠的方法。
