Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, PR China.
Jiangsu Key Laboratory for Molecular Medicine, School of Medicine, Nanjing University, Nanjing, 210093, PR China.
J Hum Genet. 2022 Aug;67(8):495-501. doi: 10.1038/s10038-022-01035-y. Epub 2022 Apr 15.
Duchenne muscular dystrophy (DMD, MIM #310200) and Becker muscular dystrophy (BMD, MIM #300376) are X-linked recessive hereditary diseases caused by pathogenic variants in the DMD gene. Genetic testing of DMD identifies a certain number of variants of uncertain clinical significance (VUS) whose functional interpretations pose a challenge for gene-based diagnosis. To improve the accuracy of variant interpretation in public mutation repositories, we used computational tools to prioritize VUS and developed a cell-based minigene assay to confirm aberrant splicing. Using this procedure, we evaluated rare variants in exon and intron 10 of the DMD gene. We demonstrated that 16 variants, including both canonical and non-canonical splice sites, altered RNA splicing in variable patterns. Using the example of exon and intron 10 of the DMD gene, we demonstrated the utility of the in vitro minigene assay in the effective assessment of the spliceogenic effect for VUS identified in clinical practice and underlined the necessity of precise variant classification. This is the first systematic characterization of DMD splicing variants, besides, through our study, some undetermined variants are demonstrated to be pathogenic by altering RNA splicing of DMD.
杜氏肌营养不良症（DMD，MIM #310200）和贝克肌营养不良症（BMD，MIM #300376）是由 DMD 基因突变引起的 X 连锁隐性遗传性疾病。DMD 基因的遗传检测可确定一定数量的临床意义不确定的变异（VUS），这些变异的功能解释对基于基因的诊断构成了挑战。为了提高公共突变库中变异解释的准确性，我们使用计算工具对 VUS 进行优先级排序，并开发了基于细胞的小基因检测来确认异常剪接。使用该程序，我们评估了 DMD 基因外显子和内含子 10 中的罕见变异。我们证明了 16 个变异，包括规范和非规范剪接位点，以不同的模式改变了 RNA 剪接。通过 DMD 基因外显子和内含子 10 的例子，我们展示了体外小基因检测在有效评估临床实践中确定的 VUS 的剪接效应中的实用性，并强调了精确变异分类的必要性。这是对 DMD 剪接变异的首次系统描述，此外，通过我们的研究，一些未确定的变异通过改变 DMD 的 RNA 剪接被证明是致病的。
