Identification and characterisation of a novel aberrant pattern of intron 1 inversion with concomitant large insertion and deletion within the F8 gene
Identification and characterisation of a novel aberrant pattern of intron 1 inversion with concomitant large insertion and deletion within the F8 gene
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F8 基因内伴随大量插入和缺失的内含子 1 倒位的新型异常模式的鉴定和表征
DOI：
10.1160/th13-10-0892
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发表时间：
2014-08-01
影响因子：
6.7
通讯作者：
Wang, Xuefeng
中科院分区：
文献类型：
--
作者：
You, Guoling;Chi, Kun;Wang, Xuefeng
内含子1倒位（Inv 1）是血友病A（HA）的一种复发性致病突变，导致1-5%的重度HA。Inv 1是内含子1内的int 1 h-1和位于F8基因端粒约125 kb处的int 1 h-2之间的染色体内同源重组的结果。在这份报告中，我们提出了一个以前未描述的异常类型的Inv 1与复杂的基因组重排在一个严重的HA家系。采用基因组步移技术确定重排断裂点;采用AccuCopy技术、AffytoScan HD CNV检测和定量PCR（qPCR）检测F8基因和X染色体的拷贝数变异（CNV）;采用逆转录PCR（RT-PCR）分析与异常Inv 1相关的F8转录本。我们已经确定了复杂重排的确切断点，并确定了插入和缺失的位置和大小。这种重排可以概括为Inv 1的异常模式，其中2.56 kb的缺失和227.3 kb的重复插入F8基因内的重新连接处。我们的研究结果表明，这种复杂的基因组重排是由两种不同的修复机制产生的叉失速和模板转换/微同源介导的断裂诱导复制（FoSTeS/MMBIR）和非等位基因同源重组（NAHR）。
Intron 1 inversion (Inv1) is a recurrent causative mutation of haemophilia A (HA) and is responsible for 1-5% of severe HA. Inv1 occurs as a result of intra-chromosomal homologous recombination between int1 h-1 within intron 1 and int1 h-2 located in approximately 125 kb telomeric to the F8 gene. In this report, we presented a previously undescribed aberrant type of Inv1 with complex genomic rearrangement in a pedigree with severe HA. The breakpoints of the rearrangement were identified by the genome walking technique; copy number variations (CNVs) of the F8 gene and X chromosome were detected by Ac-cuCopy technique, Affymetrix CytoScan HD CNV assay and quantitative PCR (qPCR); the F8 transcripts related to the aberrant Inv1 were analysed by reverse transcription PCR (RT-PCR). We have characterised the exact breakpoints of the complex rearrangement, and determined the location and size of the insertion and deletion. The rearrangements can be summarised as an aberrant pattern of Inv1 with a deletion of 2.56 kb and a duplication of 227.3 kb inserted in the rejoining junction within the F8 gene. Our results suggested that this complex genomic rearrangement was generated by two distinct repair mechanisms of fork stalling and template switching/microhomologymediated break-induced replication (FoSTeS/MMBIR) and nonallelic homologous recombination (NAHR).