珊瑚状先天性白内障一家系致病基因筛查与鉴定

目的：对一个珊瑚状先天性白内障家系进行致病基因的筛查。方法：采集家系中2例患者和1例正常对照者的外周静脉血，提取基因组DNA。选择与珊瑚状白内障相关的候选基因GJA3、GJA8、CRYGC及CRYGD设计引物，进行聚合酶链反应（ PCR）扩增候选基因，并对扩增片段进行Sanger测序。结果：该家系疾病表型为珊瑚状白内障，呈常染色体显性遗传。通过对扩增产物测序，发现家系内患者CRYGD第2个外显子第70位有1个C＞A碱基的杂合突变（ c．70C＞A），正常对照未见该点突变。结论：CRYGD基因的错义突变c．70C＞A是该珊瑚状白内障家系的致病原因。

Gene mapping and analysis of genes in a Chinese family with congenital coralliform cataract

AIM:To detect the causative mutation for congenital coralliform cataracts in a Chinese family.

METHODS:Peripheral blood samples were collected and genomic DNA was extracted. We chose four candidate genes associated with congenital coralliform cataract including GJA3,GJA8,CRYGC and CRYGD. After genomic polymerase chain reaction(PCR)performed, we sequenced the coding exons and their flanking intronic sequences of four candidate genes.

RESULTS:We ascertained a three-generation Chinese family with autosomal dominant coralliform congenital cataracts. Mutation screenings were performed for all four candidate genes, and a heterozygous variant, c.70C>A,was identified in exon 2 of CRYGD.

CONCLUSION:Our result demonstrates that a heterozygous mutation of CRYGD is responsible for the autosomal dominant congenital coralliform cataract in a three-generation Chinese pedigree.