Identification of pathogenic gene mutations in LMNA and MYBPC3 that alter RNA splicing
Identification of pathogenic gene mutations in LMNA and MYBPC3 that alter RNA splicing
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DOI：
10.1073/pnas.1707741114
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发表时间：
2017-07-18
影响因子：
11.1
通讯作者：
Seidman, J. G.
中科院分区：
文献类型：
--
作者：
Ito, Kaoru;Patel, Parth N.;Seidman, J. G.
导致单倍不足的遗传变异导致许多常染色体显性（AD）疾病。基于基因的诊断将改变典型剪接信号的变体分类为致病性，但由于对RNA剪接信号的不完全理解，可能产生或消除剪接位点的其他变体通常在临床上被分类为未知意义的变体（VUS）。为了提高对AD疾病中致病性剪接改变变体的识别，我们使用计算工具来优先考虑VUS，并开发了基于细胞的小基因剪接测定来确认异常剪接。使用这个两步程序，我们评估了两个AD心肌病基因，核纤层蛋白A/C（LMNA）和肌球蛋白结合蛋白C（MYBPC 3）的所有罕见变异。我们证明了在心肌病患者中鉴定的13种LMNA和35种MYBPC 3变异体改变了RNA剪接，代表了这些基因中已建立的破坏性剪接变异体数量增加了50%。超过一半的变异被临床诊断实验室标注为VUS。一个变体的家族分析，一个同义的LMNA VUS，表现出分离与心肌病的影响状态和改变心脏LMNA剪接。这一策略的应用应提高诊断准确性和变异分类在其他单倍不足的AD疾病。
Genetic variants that cause haploinsufficiency account for many autosomal dominant (AD) disorders. Gene-based diagnosis classifies variants that alter canonical splice signals as pathogenic, but due to imperfect understanding of RNA splice signals other variants that may create or eliminate splice sites are often clinically classified as variants of unknown significance (VUS). To improve recognition of pathogenic splice-altering variants in AD disorders, we used computational tools to prioritize VUS and developed a cell-based minigene splicing assay to confirm aberrant splicing. Using this two-step procedure we evaluated all rare variants in two AD cardiomyopathy genes, lamin A/C (LMNA) and myosin binding protein C (MYBPC3). We demonstrate that 13 LMNA and 35 MYBPC3 variants identified in cardiomyopathy patients alter RNA splicing, representing a 50% increase in the numbers of established damaging splice variants in these genes. Over half of these variants are annotated as VUS by clinical diagnostic laboratories. Familial analyses of one variant, a synonymous LMNA VUS, demonstrated segregation with cardiomyopathy affection status and altered cardiac LMNA splicing. Application of this strategy should improve diagnostic accuracy and variant classification in other haploinsufficient AD disorders.