在巴西患者中,错误地将PMS2CL伪基的频繁变体归类为PMS2功能丧失变体
Anthony Vladimir Campos Segura1, Sara Iolanda Oliveira da Silva1, Karina Miranda Santiago1
1Clinical and Functional Genomics Group, International Research Center/CIPE, A.C.Camargo Cancer Center, 440 Taguá St, São Paulo, SP, 01508-010, Brazil.
Familial cancer
|June 20, 2024
概括
在基因测试中,PMS2CL伪基因的一个常见变异经常被误认为是PMS2基因突变. 这种错误分类影响了林奇综合征的诊断,并强调了需要准确的遗传检测方法的需要.
科学领域:
- 遗传学和基因组学 遗传学和基因组学
- 分子诊断学 分子诊断学
- 癌症倾向症候群 癌症倾向症候群
背景情况:
- PMS2基因对DNA不匹配的修复至关重要,并且与林奇综合征有关,这是一种遗传性癌症倾向.
- 对PMS2变异的基因测试因存在非常相似的假基因而复杂,特别是PMS2CL.
- 之前的研究和临床报告记录了错误地归因于PMS2的变体,使准确的诊断变得复杂.
研究的目的:
- 调查一系列具有变异 (V1:c.2186_2187delTC和V2:c.2182_2184delACTinsG) 的病例,这些变异以前被分配给PMS2外体13.
- 确定这些常见变异的真实位置和临床意义.
- 为了应对伪基因干扰在PMS2遗传测试中所带来的诊断挑战.
主要方法:
- 来自647名巴西患者的遗传数据的回顾性分析,这些患者接受了多基因小组测试.
- 识别患有V1或V2变体的患者.
- 使用基因特异性PCR和PMS2转录序列测序确认变异位置.
- 与公共基因组数据库 (ExAC,gnomAD) 和ClinVar进行变异频率和分类的比较.
主要成果:
- 1.8% (12/647) 的患者携带V1/V2变体,其等位基因频率在15-34%之间.
- 基因特异性分析证实,V1和V2都代表位于PMS2CL伪基因中的相同变异,而不是PMS2基因.
- 这些变种在非洲人口中普遍存在 (2.5-5.3%),并且在ClinVar等数据库中经常被错误分类 ("不确定的意义"或"冲突") 和实验室 ("致病性").
结论:
- 在巴西和其他潜在的人群中,PMS2CL假基因的频繁变异通常被误认为是一种致病性PMS2突变.
- 这种错误分类可能导致林奇综合征的诊断不准确,并导致不适当的临床管理.
- 除了标准的短读下一代测序之外,补充分子方法对于区分PMS2和PMS2CL至关重要,确保诊断准确性.
相关概念视频
Comparing Copy Number Variations and SNPs
17.7K
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
17.7K
Incomplete Dominance
22.5K
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
22.5K
Pleiotropy
40.4K
Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
40.4K
RNA Splicing
56.3K
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
56.3K
Translation
14.8K
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
14.8K
Alternative RNA Splicing
21.1K
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
21.1K


