GJA3基因在先天性白内障患者中的突变筛查

目的研究缝隙连接蛋白基因GJA3与先天性白内障的关系。方法收集2个先天性白内障家系及30例散发先天性白内障患者,制备外周血白细胞基因组DNA,PCR扩增GJA3基因的外显子及其邻近的内含子,应用SSCP法检测并发现变异条带,将相应的扩增产物回收并纯化后进行GJA3基因测序。测序结果与GenBank公布的GJA3基因正常序列比对找出突变。结果在68例先天性白内障患者中,仅发现1例患者其GJA3基因外显子D段扩增产物SSCP电泳有3条DNA单链带,而其他患者为2条带。将该段序列进行PCR扩增并测序,于编码区未见任何突变,仅在非编码区域发现碱基CA的缺失。结论GJA3基因与本组先天性白内障无关。先天性白内障临床表型与基因型之间的确切关系有待进一步的研究。

Screening of GJA3 gene mutation in patients with congenital cataract

Objective To screen mutation of GJA3 gene in patients with congenital cataract.Methods Two families and 30 sporadic patients with congenital cataract were enrolled.Blood samples were taken for genomic DNA preparation.Single-strand conformation polymorphism (SSCP) method was performed to screen the mutation of GJA3 gene,and the abnormal bands were detected by 10% polyacrylamide gels stained by silver.The sequence of abnormal bands was compared with the normal sequences offered by GenBank.Results Only one abnormal band was found by SSCP in one of 68 patients.Sequence analysis proved that the abnormal band had a deletion of CA in noncoding region of GJA3 gene.Conclusion The phenotypes of these patients are not caused by mutation of GJA3 gene.Further studies should be done to investigate the relationship between genotypes and clinical phenotype in patients with congenital cataract.