摘要
目的对中国一常染色体显性遗传先天性核性颗粒状白内障家系进行致病基因的定位与候选基因突变检测。方法采集家系成员外周静脉血,提取基因组DNA。选用ABI公司提供的荧光标记物进行基因扫描。首先对已报道的先天性白内障候选区域进行初步扫描,数据经连锁分析,计算对数优势计分(LOD)值。在连锁阳性区域内选取更加精细的荧光标记物进行进一步精细扫描。数据经连锁分析,确定最大LOD值。数据汇总进行单体型分析。候选基因直接测序检测基因突变。结果两点间连锁分析结果,在荧光标记物D13S175处获得最大LOD值Zmax=5.90(θmax=0.00)。排列单体型后将致病基因定位于荧光标记物D13S1316和D13S1275之间,位于染色体13q12.11。候选基因直接测序发现α3连接蛋白基因(GJA3)第2外显子第427碱基一个G->A的点突变,导致多肽编码序列的第143位甘氨酸变为精氨酸(G143R)。结论本研究将一中国先天性核性颗粒状白内障家系的致病基因定位于染色体13q12.11区域内,并在GJA3基因发现一个新的点突变。
Objective To map and detect the gene responsible for autosomal dominant inherited congenital nuclear cataract in a Chinese family. Methods The peripheral blood samples were collected from the members in pedigree. The genomic DNA was extracted from the blood samples. A genescan was performed using about 400 microsatellite markers （ABI）. Linkage analysis was processed to define the region of disease gene. High density primers labeled with fluorescent stain for the positive region were adopted for fine targeting, and haplotype analysis was processed. Mutation detection was carried out by sequencing candidate genes. Results The maximum two-point LOD scores was obtained at D13S175, Zmax =5.90 （θmax =0. 00）. After fine targeting and haplotype analysis, the gene was located within a 6.99 centimorgan （cM） region between D13S1316 and D13S1275 on chromosome 13q12. 11. Direct sequencing of the candidate gene revealed a G- 〉 A transition in exon 2 of GJA3 （ gap junction protein al- pha-3 ）. This single-nucleotide change resulted in the substitution of a highly conserved glycine by arginine （G143R）. Cortelusiort The present study has mapped the disease gene to chro- mosome 13q12. 11 and identified a novel mutation in GJA3 associated with congenital nuclear cataract in a Chinese family.
出处
《哈尔滨医科大学学报》
CAS
北大核心
2014年第2期128-132,共5页
Journal of Harbin Medical University
基金
黑龙江省教育厅面上项目(12531223)
