Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.
Eur J Hum Genet. 2010 Jul;18(7):783-7. doi: 10.1038/ejhg.2010.20. Epub 2010 Feb 24.
The constitutional t(11;22)(q23;q11) is a well-known recurrent non-Robertsonian translocation in humans. Although translocations generally occur in a random fashion, the break points of t(11;22)s are concentrated within several hundred base pairs on 11q23 and 22q11. These regions are characterized by palindromic AT-rich repeats (PATRRs), which appear to be responsible for the genomic instability. Translocation-specific PCR detects de novo t(11;22)s in sperm from healthy males at a frequency of 1/10(4)-10(5), but never in lymphoblasts, fibroblasts or other human somatic cell lines. This suggests that the generation of t(11;22) rearrangement is linked to gametogenesis, although female germ cells have not been tested. Here, we have studied eight cases of de novo t(11;22) to determine the parental origin of the translocation using the polymorphisms on the relevant PATRRs. All of the eight translocations were found to be of paternal origin. This result implicates a possible novel mechanism of sperm-specific generation of palindrome-mediated chromosomal translocations.
11;22(tq23;q11) 染色体平衡易位是人类中一种常见的非罗伯逊易位。虽然易位通常是随机发生的，但 t(11;22)的断裂点集中在 11q23 和 22q11 的几百个碱基对范围内。这些区域的特征是回文 AT 富含重复序列 (PATRRs)，这似乎是基因组不稳定的原因。易位特异性 PCR 在健康男性精子中检测到新生 t(11;22)的频率为 1/10(4)-10(5)，但在淋巴母细胞、成纤维细胞或其他人类体细胞系中从未检测到。这表明 t(11;22)重排的产生与配子发生有关，尽管尚未对雌性生殖细胞进行测试。在这里，我们研究了 8 例新发 t(11;22)，使用相关 PATRR 上的多态性来确定易位的亲本来源。所有 8 个易位均被发现来自父本。这一结果暗示了一种可能的新的精子特异性回文介导染色体易位发生的机制。
