Yu C W, Borgaonkar D S, Bolling D R
Hum Hered. 1978;28(3):210-225. doi: 10.1159/000152960.
Break points of structural rearrangements of human chromosomes can be identified by banding techniques. The present study attempts to analyze the randomness and the distribution of the reported spontaneous break points in the human genome. Reports of break points in structural rearrangements of human chromosomes from the published sources up to October 1976 were analyzed. Based on the assumption that each unit length of band has an equal chance of being broken, chi2 tests show that positions of breakage are highly non-random; that is, breaks are more frequent in the negative band areas and in the centromeric and terminal regions. In double-break rearrangements the same band types tend to rejoin. The distribution of breaks is not proportional to the chromosome length. The longer chromosomes (i.e., 1--12, X) have a lower number of breaks per unit length, while the shorter chromosomes (i.e., 13--22, Y) have a greater number of breaks per unit length with the exception of chromosomes 4, 9, 10, 16, 17, 19, 20 and X. Out of the whole genome, chromosomes 9, 13, 18, 21, 22 and Y have the most breaks per unit length and chromosomes 16, 6, 2, 3 and 19 have the fewest. 18p11, 21q22 and Yp11 are the three bands with most frequent breaks. There are 53 bands where no breaks have been reported.
人类染色体结构重排的断点可通过显带技术识别。本研究试图分析人类基因组中已报道的自发断点的随机性和分布情况。对截至1976年10月已发表资料中人类染色体结构重排断点的报告进行了分析。基于每个带的单位长度被打断的机会均等这一假设，卡方检验表明断裂位置高度非随机；也就是说，在负带区域以及着丝粒和末端区域断裂更为频繁。在双断点重排中，相同的带型倾向于重新连接。断点的分布与染色体长度不成比例。较长的染色体（即1 - 12号染色体、X染色体）每单位长度的断点数量较少，而较短的染色体（即13 - 22号染色体、Y染色体）每单位长度的断点数量较多，但4号、9号、10号、16号、17号、19号、20号染色体和X染色体除外。在整个基因组中，9号、13号、18号、21号、22号染色体和Y染色体每单位长度的断点最多，16号、6号、2号、3号和19号染色体的断点最少。18p11、21q22和Yp11是断点最频繁出现的三个带。有53个带未报告有断点。
