Cai Su-Ping, Lu Lan, Wang Xi-Zhen, Wang Yun, He Fen, Fan Ning, Weng Jing-Ning, Zhang Jun-Hua, Liu Xu-Yang
Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen 518000, Guangdong Province, China.
Department of Ophthalmology, Fujian Medical University Union Hospital, Fujian Medical University College of Medical Technology and Engineering, Fuzhou 350001, Fujian Province, China.
Int J Ophthalmol. 2021 Jun 18;14(6):800-804. doi: 10.18240/ijo.2021.06.03. eCollection 2021.
To investigate the causal gene mutation and clinical characteristics for two Chinese families with autosomal dominant congenital coralliform cataract.
Two Chinese pedigrees with congenital cataract were investigated. Routine ophthalmic examinations were performed on all patients and non-affected family members. Peripheral blood samples were collected, and the genomic DNAs were extracted. The coding regions of proband's DNAs were analyzed with cataract gene panel. The identified mutation was amplified by polymerase chain reaction, and automated sequencing was performed in other members of two families to verify whether the mutated gene was co-segregated with the disease.
Congenital coralliform cataract was inherited in an autosomal dominant mode in both pedigrees. For each family, more than half of the family members were affected. All patients presented with severe visual impairment after birth as a result of bilateral symmetric coralliform lens opacification. An exact the same defect in the same gene, a heterozygous mutation of c.70C>A (p. P24T) in exon 2 of γD-crystallin gene, was detected in both probands from each family. Sanger sequencing analysis demonstrated that the mutated was co-segregated in these two families.
A c.70C>A (p. P24T) variant in gene was reconfirmed to be the causal gene in two Chinese pedigrees. It is known that mutated caused most of the congenital coralliform cataracts, suggesting that the gene is associated with coralliform congenital cataract.
研究两个常染色体显性遗传性先天性珊瑚状白内障中国家系的致病基因突变及临床特征。
对两个先天性白内障中国家系进行调查。对所有患者及未患病家庭成员进行常规眼科检查。采集外周血样本，提取基因组DNA。利用白内障基因检测板分析先证者DNA的编码区。通过聚合酶链反应扩增鉴定出的突变，并对两个家系的其他成员进行自动测序，以验证突变基因是否与疾病共分离。
两个家系中先天性珊瑚状白内障均以常染色体显性方式遗传。每个家系中，超过半数的家庭成员患病。所有患者均因双侧对称性晶状体珊瑚状混浊出生后即出现严重视力障碍。在每个家系的两名先证者中均检测到同一基因完全相同的缺陷，即γD-晶状体蛋白基因第2外显子的杂合突变c.70C>A（p.P24T）。桑格测序分析表明该突变在这两个家系中与疾病共分离。
再次证实γD-晶状体蛋白基因中的c.70C>A（p.P24T）变异是两个中国家系的致病基因。已知γD-晶状体蛋白基因突变导致大多数先天性珊瑚状白内障，提示γD-晶状体蛋白基因与珊瑚状先天性白内障相关。
