Institute for Comprehensive Medical Science, Fujita Health University, Aichi, Japan.
Hum Mol Genet. 2010 Jul 1;19(13):2630-7. doi: 10.1093/hmg/ddq150. Epub 2010 Apr 13.
The constitutional t(11;22) is the most frequent recurrent non-Robertsonian translocation in humans, the breakpoints of which are located within palindromic AT-rich repeats on 11q23 and 22q11 (PATRR11 and PATRR22). Genetic variation of the PATRR11 was found to affect de novo t(11;22) translocation frequency in sperm derived from normal healthy males, suggesting the hypothesis that polymorphisms of the PATRR22 might also influence the translocation frequency. Although the complicated structure of the PATRR22 locus prevented determining the genotype of the PATRR22 in each individual, genotyping of flanking markers as well as identification of rare variants allowed us to demonstrate an association between the PATRR22 allele type and the translocation frequency. We found that size and symmetry of the PATRR22 affect the de novo translocation frequency, which is lower for the shorter or more asymmetric versions. These data lend support to our hypothesis that the PATRRs form secondary structures in the nucleus that induce genomic instability leading to the recurrent translocation.
t(11;22) 是人类最常见的非罗伯逊易位,其断裂点位于 11q23 和 22q11 上的回文 AT 富含重复序列(PATRR11 和 PATRR22)内。发现 PATRR11 的遗传变异会影响来自正常健康男性精子中的新生 t(11;22)易位频率,这表明 PATRR22 的多态性也可能影响易位频率。尽管 PATRR22 基因座的复杂结构阻止了在每个个体中确定 PATRR22 的基因型,但侧翼标记的基因分型以及稀有变体的鉴定使我们能够证明 PATRR22 等位基因类型与易位频率之间存在关联。我们发现,PATRR22 的大小和对称性会影响新生易位频率,较短或更不对称的版本频率较低。这些数据支持我们的假设,即 PATRR 在核内形成二级结构,导致基因组不稳定性,从而导致反复易位。