Vanin E F, Henthorn P S, Kioussis D, Grosveld F, Smithies O
Cell. 1983 Dec;35(3 Pt 2):701-9. doi: 10.1016/0092-8674(83)90103-4.
Two independent gamma delta beta-thalassemias are each associated with large deletions. We show, by comparing DNA sequences, that the deletions are due to non-homologous DNA exchanges. The 5' breakpoints are located approximately the same distance apart and in the same order along the DNA as their 3' breakpoints. Two independent cases of hereditary persistence of fetal hemoglobin, also involving large deletions, show the same unexpected relationship between their 5' and 3' breakpoints. This relationship is most simply explained if, within each pair, the deletions are of approximately the same length. The results suggest that the four deletions were generated by a common mechanism. Perhaps their 5' and 3' breakpoints are physically close in the nucleus, although far apart on the linear DNA.
两种独立的γδβ地中海贫血均与大片段缺失相关。通过比较DNA序列，我们发现这些缺失是由非同源DNA交换所致。5'断点沿DNA与其3'断点的距离大致相同且顺序相同。另外两例独立的胎儿血红蛋白遗传性持续存在病例，同样涉及大片段缺失，其5'和3'断点之间也呈现出相同的意外关系。如果每一对中的缺失长度大致相同，那么这种关系就能得到最简单的解释。结果表明这四个缺失是由一种共同机制产生的。也许它们的5'和3'断点在细胞核中实际距离很近，尽管在线性DNA上相距很远。
