Rivera H, García-Esquivel L, Jiménez-Sáinz M, Vaca G, Ibarra B, Cantú J M
Clin Genet. 1987 Jun;31(6):393-8. doi: 10.1111/j.1399-0004.1987.tb02831.x.
A 5-month-old girl had a typical 12p trisomy syndrome due to a monocentric i(12p) present in a 46-chromosome complement that also included the translocation of all 12q onto the 8p telomere; i.e., her complex karyotype could be written as 46,XX,-8,-12, +der(8),t(8;12)(p23.3;cen),+i(12p). The present concurrence of a whole-arm q translocation and an i(p) for a single chromosome, along with six previous similar instances involving chromosomes 4, 5 and 9, suggests the following origin for such a special rearrangement: a centric fission in G1 initially yielding two telocentrics; at the next replication, the tel(q) translocates onto a nonhomologous telomere (centromere-telomere fusion), whereas the tel(p) becomes an i(p). This mechanism can be either meiotic or postzygotic and surmises that the translocated long arm retains a partial centromere, which subsequently is inactivated and loses its staining properties.
一名5个月大的女孩患有典型的12号染色体三体综合征，其46条染色体核型中存在一个单中心i(12p)，该核型还包括整个12号染色体长臂易位到8号染色体短臂端粒上；也就是说，她的复杂核型可写成46,XX,-8,-12,+der(8),t(8;12)(p23.3;cen),+i(12p)。目前单个染色体出现全臂q易位和i(p)的情况，以及之前涉及4号、5号和9号染色体的6个类似病例，提示了这种特殊重排的起源如下：G1期的着丝粒分裂最初产生两个端着丝粒染色体；在下一次复制时，端(q)易位到非同源端粒上(着丝粒-端粒融合)，而端(p)则成为i(p)。这种机制可以是减数分裂的，也可以是合子后发生的，并且推测易位的长臂保留了部分着丝粒，随后该着丝粒失活并失去其染色特性。
