PDF(Pubmed)
Abstract：
BACKGROUND: Large deletions and duplications within the low-density lipoprotein receptor (LDLR) gene make up approximately 10% of LDLR pathogenic variants found in Czech patients with familial hypercholesterolemia. The goal of this study was to test the hypothesis that all probands with each rearrangement share identical breakpoints inherited from a common ancestor and to determine the role of Alu repetitive elements in the generation of these rearrangements.
METHODS: The breakpoint sequence was determined by PCR amplification and Sanger sequencing. To confirm the breakpoint position, an NGS analysis was performed. Haplotype analysis of common LDLR variants was performed using PCR and Sanger sequencing.
RESULTS: The breakpoints of 8 rearrangements within the LDLR gene were analysed, including the four most common LDLR rearrangements in the Czech population (number of probands ranging from 8 to 28), and four less common rearrangements (1-4 probands). Probands with a specific rearrangement shared identical breakpoint positions and haplotypes associated with the rearrangement, suggesting a shared origin from a common ancestor. All breakpoints except for one were located inside an Alu element. In 6 out of 8 breakpoints, there was high homology (≥ 70%) between the two Alu repeats in which the break occurred.
CONCLUSIONS: The most common rearrangements of the LDLR gene in the Czech population likely arose from one mutational event. Alu elements likely played a role in the generation of the majority of rearrangements inside the LDLR gene.
METHODS: The breakpoint sequence was determined by PCR amplification and Sanger sequencing. To confirm the breakpoint position, an NGS analysis was performed. Haplotype analysis of common LDLR variants was performed using PCR and Sanger sequencing.
RESULTS: The breakpoints of 8 rearrangements within the LDLR gene were analysed, including the four most common LDLR rearrangements in the Czech population (number of probands ranging from 8 to 28), and four less common rearrangements (1-4 probands). Probands with a specific rearrangement shared identical breakpoint positions and haplotypes associated with the rearrangement, suggesting a shared origin from a common ancestor. All breakpoints except for one were located inside an Alu element. In 6 out of 8 breakpoints, there was high homology (≥ 70%) between the two Alu repeats in which the break occurred.
CONCLUSIONS: The most common rearrangements of the LDLR gene in the Czech population likely arose from one mutational event. Alu elements likely played a role in the generation of the majority of rearrangements inside the LDLR gene.
摘要：
背景：低密度脂蛋白受体（LDLR）基因内的大量缺失和重复构成了捷克家族性高胆固醇血症患者中发现的LDLR致病变异的约10％。这项研究的目的是检验以下假设：每个重排的所有先证都共享从共同祖先继承的相同断点，并确定Alu重复元素在这些重排产生中的作用。
方法:通过PCR扩增和Sanger测序确定断点序列。要确认断点位置，进行了NGS分析。使用PCR和Sanger测序进行常见LDLR变体的单倍型分析。
结果：分析了LDLR基因内8个重排的断点，包括捷克人口中四种最常见的LDLR重新安排（先证者的数量从8到28），和四个不太常见的重排(1-4先证者)。具有特定重排的前带共享相同的断点位置和与重排相关的单倍型，暗示共同祖先的共同起源。除一个断点外，所有断点都位于Alu元素内部。在8个断点中的6个中，发生断裂的两个Alu重复序列之间具有很高的同源性（≥70％）。
结论：捷克人群中最常见的LDLR基因重排可能源于一个突变事件。Alu元素可能在LDLR基因内部大多数重排的产生中起作用。
方法:通过PCR扩增和Sanger测序确定断点序列。要确认断点位置，进行了NGS分析。使用PCR和Sanger测序进行常见LDLR变体的单倍型分析。
结果：分析了LDLR基因内8个重排的断点，包括捷克人口中四种最常见的LDLR重新安排（先证者的数量从8到28），和四个不太常见的重排(1-4先证者)。具有特定重排的前带共享相同的断点位置和与重排相关的单倍型，暗示共同祖先的共同起源。除一个断点外，所有断点都位于Alu元素内部。在8个断点中的6个中，发生断裂的两个Alu重复序列之间具有很高的同源性（≥70％）。
结论：捷克人群中最常见的LDLR基因重排可能源于一个突变事件。Alu元素可能在LDLR基因内部大多数重排的产生中起作用。
