Rivera H, Domínguez M G, Vásquez-Velásquez A I, Lurie I W
División de Genética, CIBO, Instituto Mexicano del Seguro Social, Guadalajara, Mexico.
Cytogenet Genome Res. 2013;141(1):58-63. doi: 10.1159/000351184. Epub 2013 May 30.
We compiled 104 constitutional de novo or sporadic rearranged chromosomes mimicking recombinants from a parental pericentric inversion in order to comment on their occurrence and parental derivation, meiotic or postzygotic origin, mean parental ages, and underlying pathways. Chromosomes involved were 1-9, 13-18, 20-22, and X (64 autosomes and 40 X chromosomes). In the whole series, mean paternal and maternal ages in cases of paternal (proved or possible; n=29) or maternal (proved or possible; n=36) descent were 31.14 and 28.31 years, respectively. Rearranged X chromosomes appeared to be of paternal descent and to arise through intrachromosomal non-allelic homologous recombination (NAHR), whereas rec-like autosomes were of either maternal or paternal origin and resulted from mechanisms proper of non-recurrent rearrangements. Except for some mosaic cases, most rearranged chromosomes apparently had a meiotic origin. Except for 8 rearranged X chromosomes transmitted maternally, all other cases compiled here were sporadic. Hence, the recurrence risk for sibs of propositi born to euploid parents is virtually zero, regardless of the imbalance's size. In brief, recombinant-like or rea chromosomes are not related to advanced parental age, may (chromosome X) or may not (autosomes) have a parent-of-origin bias, arise in meiosis or postzygotically, and appear to be mediated by NAHR, nonhomologous end joining, and telomere transposition. Because rearranged chromosomes 10, 11, and Y are also on record, albeit just in abstracts or listed in large series, we remark that all chromosomes can undergo this distinct rearrangement, even if it is still to be described for pairs 12 and 19.
我们收集了104条新生的或散发的结构重排染色体，这些染色体模拟了亲本臂间倒位产生的重组体，目的是对它们的出现情况、亲本来源、减数分裂或合子后起源、亲本平均年龄以及潜在途径进行评论。涉及的染色体为1 - 9号、13 - 18号、20 - 22号和X染色体（64条常染色体和40条X染色体）。在整个系列中，父系（已证实或可能；n = 29）或母系（已证实或可能；n = 36）遗传情况下的父本和母本平均年龄分别为31.14岁和28.31岁。重排的X染色体似乎来自父系，通过染色体内非等位同源重组（NAHR）产生，而类rec常染色体则来自母系或父系，是由非反复重排的机制导致的。除了一些嵌合病例外，大多数重排染色体显然起源于减数分裂。除了8条通过母系传递的重排X染色体外，这里收集的所有其他病例都是散发的。因此，对于染色体数目正常的父母所生的先证者的同胞，复发风险几乎为零，无论不平衡的大小如何。简而言之，重组样或rea染色体与父母年龄增长无关，可能（X染色体）或可能不（常染色体）具有亲本来源偏向，在减数分裂或合子后产生，并且似乎由NAHR、非同源末端连接和端粒转位介导。由于10号、11号和Y号重排染色体也有记录，尽管只是在摘要中或在大型系列中列出，我们指出所有染色体都可能经历这种独特的重排，即使12号和19号染色体对的这种重排仍有待描述。
