先天性后极性白内障超微结构分析及突变基因筛查  

Study on ultrastructure changes and genetic mutation of a congenital posterior polar cataract

作　　者：朱亚楠[1] 申屠形超[1] 王玮[1] 

机构地区：[1]浙江大学医学院附属第二医院眼科中心,浙江省杭州市310009

出　　处：《眼科新进展》2011年第12期1145-1147,共3页Recent Advances in Ophthalmology

基　　金：浙江省科技计划项目资助(编号:2008C23075);浙江省医药卫生科技计划项目(编号:2010QMA012)~~

摘　　要：目的探讨一先天性后极性白内障家系晶状体的超微结构改变,并初步筛查其致病基因。方法收集一常染色体显性遗传性先天性后极性白内障家系资料,对家系成员行眼部检查;在透射电镜下观察晶状体细胞超微结构的改变;选择CRYAB、CRYBA1/A3、CRYBB2、GJA8、CHMP4B、PITX3和EPHA2这7个热点基因进行突变位点筛查。结果根据家系图分析该家系为垂直遗传,符合单基因常染色体显性遗传特点。裂隙灯显微镜下检查示全部患者晶状体混浊形态完全相同。透射电镜下发现患者前囊面晶状体上皮细胞排列紧密,结构完整,未见特异性病理变化;前皮质晶状体纤维细胞排列紧密,细胞内密度均一一致,但后皮质晶状体纤维细胞内出现斑驳状中高密度异常颗粒沉着。热点基因筛查显示:7个候选基因的外显子及其邻近内含子序列与基因库对照未发现任何突变。结论本研究将后极性白内障病变定位于后皮质晶状体纤维细胞,排除了前囊面晶状体上皮细胞及前皮质晶状体纤维细胞。此家系携带的遗传突变位点位于尚未见报道的与后极性白内障相关的致病基因上。Objective To report the ultrastructure changes of and screen the genetic mutation for a posterior polar autosomal dominant congenital cataract（ADCC） in a Chinese family.Methods A four-generation Chinese family affected by posterior polar ADCC was analyzed.Clinical examination and transmission electron microscopy analysis of the removed lens tissue were performed.Blood samples were taken for DNA extraction,and seven hot genes,including CRYAB,CRYBA1/A3,CRYBB2,GJA8,CHMP4B,PITX3 and EPHA4 were screened for genetic mutation.Results We identified that this family was vertical heredity in family tree,and was consistent with heredity characteristics of autosomal dominant inheritance.Slit lamp microscope showed that lens haze was similar in all patients.Transmission electron microscope showed that lens epithelial cells at anterior capsule were with close arrange,complete structure,and without specific pathological change.The lens epithelial cells under anterior cortex were with close arrange and similar intracellular density,while the lens fiber cells in the posterior cortex displayed mottling medium-high density deposition of specific articles.Screening of hot genes：no mutation was found for exon and neighbouring intron of 7 hot genes as compared with Gene Bank.Conclusion The pathological changes of posterior polar cataract is located at lens fiber cells at posterior cortex,with exception of lens epithelial cells at anterior capsule or lens fiber cells at anterior cortex.The mutation of this family is located at virulence genes associated with posterior polar cataract,which has not been reported.

关 键 词：先天性白内障 后极性白内障 超微结构 基因突变 

分 类 号：R776[医药卫生—眼科]