文章：

Alu介导的外显子11重复与缺失是PALB2失活的常见机制，易导致个体罹患遗传性乳腺癌-卵巢癌综合征

Alu–Mediated Duplication and Deletion of Exon 11 Are Frequent Mechanisms ofPALB2Inactivation, Predisposing Individuals to Hereditary Breast–Ovarian Cancer Syndrome

原文发布日期：30 November 2024

DOI: 10.3390/cancers16234022

类型: Article

开放获取: 是

英文摘要：

Background/Objective: Large genomic rearrangements ofPALB2gene, particularly deletions and duplications, have been linked to hereditary breast–ovarian cancer. Our research specifically focuses on delineating the intronic breakpoints associated with rearrangements ofPALB2exon 11, which is crucial for understanding the mechanisms underlying these genomic changes in patients with hereditary breast and ovarian syndrome. Methods: By using next-generation sequencing, we identified one duplication and three deletions ofPALB2exon 11, confirmed by Multiplex Ligation-Dependent Probe Amplification analysis. To assess the impact on transcription and potential splicing issues, reverse-transcription PCR was performed on patients’ RNA. For the detailed characterization of intronic breakpoints, the primer walking approach and long-range PCR were implemented, followed by Sanger sequencing. Results: Our analysis revealed a tandem duplication of 5134 base pairs (bp) mediated byAluYrepeats located in introns 10 and 11, respectively. Moreover, identical deletions were identified in three unrelated patients, encompassing an approximate 8050 bp region mediated byAluSxelements. Both genomic alterations resulted in a truncatedPALB2protein due to the introduction of a premature stop codon. Conclusions: This study underscores the remarkable instability of intronic regions flanking exon 11 ofPALB2and identifies a previously unreported hotspot involvingAlurepeats with very high sequence homology in introns 10 and 11 of the gene. Our findings suggest avenues for further research, such as investigating the prevalence of similar genomic rearrangements in larger cohorts and exploring functional studies to understand how these alterations contribute to hereditary breast cancer pathogenesis.

摘要翻译： 

背景/目的：PALB2基因的大规模基因组重排，特别是缺失和重复，已被证实与遗传性乳腺癌-卵巢癌相关。本研究重点在于解析与PALB2基因第11号外显子重排相关的内含子断裂点，这对于理解遗传性乳腺癌-卵巢癌综合征患者基因组变异的机制至关重要。方法：通过新一代测序技术，我们识别出一例重复和三例缺失的PALB2基因第11号外显子，并通过多重连接依赖性探针扩增分析予以确认。为评估其对转录的影响及潜在的剪接问题，我们对患者RNA进行了逆转录PCR。为详细表征内含子断裂点，我们采用引物步移法和长距离PCR，随后进行Sanger测序。结果：分析显示，一个由位于第10和11内含子中的AluY重复序列介导的5134碱基对串联重复。此外，在三位无亲缘关系的患者中发现了相同的缺失，涉及约8050碱基对的区域，由AluSx元件介导。这两种基因组改变均因引入提前终止密码子而导致PALB2蛋白截短。结论：本研究揭示了PALB2基因第11号外显子侧翼内含子区域的高度不稳定性，并识别出一个先前未报道的热点区域，涉及该基因第10和11内含子中序列同源性极高的Alu重复序列。我们的发现为进一步研究提供了方向，例如在更大群体中调查类似基因组重排的普遍性，以及通过功能研究探索这些变异如何促进遗传性乳腺癌的发病机制。

原文链接：

Alu–Mediated Duplication and Deletion of Exon 11 Are Frequent Mechanisms ofPALB2Inactivation, Predisposing Individuals to Hereditary Breast–Ovarian Cancer Syndrome