Mattei M G, Mattei J F, Guichaoua M, Giraud F
Hum Genet. 1981;59(4):310-6. doi: 10.1007/BF00295463.
Pericentric inversion of chromosome 9, a common abnormality, has been much studied because of its possible genetic effect. Apart from total inversion, in which the whole heterochromatic segment of chromosome 9 appears to be situated on the short arm, some authors describe partial inversion, in which the heterochromatin is found partly on the long arm and partly on the short arm. Our study indicates that firstly, the heterochromatic segment of chromosome 9 is composed of two biochemically different subunits: the heterochromatin of the centromere itself and the heterochromatin of the secondary constriction. Secondly, it suggests that partial inversion of the secondary constriction of chromosome 9 is an unusual event, as the majority of published cases can be interpreted as the result of an increase in the centromeric heterochromatin without alteration of the secondary constriction.
9号染色体臂间倒位是一种常见的异常情况，由于其可能产生的遗传效应，已得到大量研究。除了整个异染色质区段似乎都位于短臂上的完全倒位外，一些作者还描述了部分倒位，即异染色质部分位于长臂，部分位于短臂。我们的研究表明，首先，9号染色体的异染色质区段由两个生化性质不同的亚单位组成：着丝粒本身的异染色质和次缢痕的异染色质。其次，这表明9号染色体次缢痕的部分倒位是一种不寻常的事件，因为大多数已发表的病例可解释为着丝粒异染色质增加而次缢痕未改变的结果。
