Lie-Injo L E, Herrera A R, Lebo R V, Hassan K, Lopez C G
Am J Hematol. 1985 Mar;18(3):289-96. doi: 10.1002/ajh.2830180311.
Restriction enzyme analysis of the alpha and zeta globin genes was carried out in four cases of Hb Bart's hydrops fetalis, in three patients with Hb H disease without Hb CoSp, in three patients with Hb H disease with Hb CoSp, in 47 individuals with alpha thalassemia trait, and in 47 normal individuals. All four cases of Hb Bart's hydrops fetalis resulted from deletions of alpha 1 and alpha 2 globin genes which did not extend to the psi zeta 1 and zeta 2 globin genes. The same type of deletion was observed in alpha thal1 carriers, but two newborns (one Malay and one of Chinese extraction) had a nondeletion type of alpha thal1 which was confirmed by quantitative alpha globin gene analysis. In addition, two other newborns diagnosed as alpha thal1 trait carriers (one Malay, one Chinese) were shown to have a deletion of both alpha globin genes by quantitative alpha globin gene analysis, but further testing with zeta globin gene probe failed to reveal an abnormal fragment length characteristic of an alpha globin gene deletion. We believe that this last condition is due to a large deletion which includes all alpha globin genes and all zeta globin genes on the same chromosome. On another front, Bgl II restriction analysis of all four Hb Bart's hydrops fetalis cases and the alpha thal1 trait carriers showed a 10.5-kb Bgl II restriction fragment, in the hydrops fetalis as a single band, while in the carriers this 10.5-kb fragment was accompanied by the usual normal 12.5-kb and 11.3-kb fragments. We report that this 10.5-kb fragment, previously thought to be specific for the Southeast Asian alpha thal1 gene deletion, is also common in normal individuals. Nevertheless, digestion with other enzymes can clearly differentiate the alpha thal1 and normal genotypes. We distinguish the findings in the alpha thalassemias from the extensive DNA polymorphism in the region of the alpha and zeta globin genes.
对4例巴氏水肿胎儿血红蛋白（Hb Bart's）、3例无血红蛋白CoSp的血红蛋白H病患者、3例有血红蛋白CoSp的血红蛋白H病患者、47例α地中海贫血特征个体以及47例正常个体进行了α和ζ珠蛋白基因的限制性内切酶分析。所有4例巴氏水肿胎儿血红蛋白均由α1和α2珠蛋白基因缺失所致，且缺失未延伸至ψζ1和ζ2珠蛋白基因。在α地中海贫血1（αthal1）携带者中观察到相同类型的缺失，但有2名新生儿（1名马来人和1名华裔）具有非缺失型αthal1，这通过定量α珠蛋白基因分析得以证实。此外，另外2名被诊断为αthal1特征携带者的新生儿（1名马来人，1名华裔）经定量α珠蛋白基因分析显示α珠蛋白基因均缺失，但用ζ珠蛋白基因探针进一步检测未发现α珠蛋白基因缺失的异常片段长度特征。我们认为最后这种情况是由于同一染色体上包括所有α珠蛋白基因和所有ζ珠蛋白基因的大片段缺失所致。另一方面，对所有4例巴氏水肿胎儿血红蛋白病例和αthal1特征携带者进行Bgl II限制性分析显示，在水肿胎儿中为一条单一的10.5 kb Bgl II限制性片段，而在携带者中，该10.5 kb片段伴有通常的正常12.5 kb和11.3 kb片段。我们报告称，此前认为特定于东南亚αthal1基因缺失的这条10.5 kb片段在正常个体中也很常见。然而，用其他酶消化可清楚区分αthal1和正常基因型。我们将α地中海贫血的这些发现与α和ζ珠蛋白基因区域广泛的DNA多态性区分开来。
