Zhang Jing-Jin, Cao Zong-Fu, Zhou Bi-Ting, Yang Ju-Hua, Li Zhong, Lin Shuang, Chen Xiao-Le, Zhang Nan-Wen, Ye Qin, Ma Xu, Zhu Yi-Hua
Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University; Fujian Institute of Ophthalmology; Fujian Provincial Clinical Medical Research Center of Eye Diseases and Optometry, Fuzhou 350005, Fujian Province, China.
Department of Ophthalmology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou 350005, Fujian Province, China.
Int J Ophthalmol. 2024 Jun 18;17(6):1007-1017. doi: 10.18240/ijo.2024.06.04. eCollection 2024.
To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity.
A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited. Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals. Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery. The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software. Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2 (EPHA2). Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins. The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay, respectively. The cell migration was analyzed by wound healing assay. Zebrafish model was generated by ectopic expression of human /p.R957P mutant to demonstrate whether the mutant could cause lens opacity .
A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif (SAM) domain of . Functional studies demonstrated the variant's impact: reduced EPHA2 protein expression, altered subcellular localization, and disrupted interactions with other lens membrane proteins. This mutant notably enhanced human lens epithelial cell migration, and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human /p.R957P mutant under differential interference contrast (DIC) optics.
Novel pathogenic c.2870G>C variant of in a Chinese congenital cataract family contributes to disease pathogenesis.
鉴定一个患有先天性后极性白内障的中国家系中的基因缺陷并评估其致病性。
招募了一个患常染色体显性先天性白内障的四代中国家系。19名个体参与了本研究，包括5名患者和14名未患病个体。采用桑格测序法对27个先天性白内障致病基因的热点区域进行变异检测。依据美国医学遗传学学会的指南和InterVar软件评估变异的致病性。应用共聚焦显微镜检测荧光标记的A类 Ephrin受体2（EPHA2）的亚细胞定位。实施免疫共沉淀试验以评估EphA2与其他晶状体膜蛋白之间的相互作用。分别通过逆转录聚合酶链反应（qRT-PCR）和蛋白质免疫印迹法分析mRNA和蛋白质表达。通过伤口愈合试验分析细胞迁移情况。通过异位表达人/p.R957P突变体构建斑马鱼模型，以证明该突变体是否会导致晶状体混浊。
在 的无菌α基序（SAM）结构域中鉴定出一个新的错义致病变异c.2870G>C。功能研究证实了该变异的影响：EPHA2蛋白表达降低、亚细胞定位改变以及与其他晶状体膜蛋白的相互作用被破坏。该突变体显著增强了人晶状体上皮细胞的迁移能力，并在微分干涉差（DIC）光学下异位表达人/p.R957P突变体时，诱导斑马鱼晶状体出现中央混浊区域和粗糙表面。
中国先天性白内障家系中 的新型致病c.2870G>C变异促成了疾病的发病机制。
