Avellino型角膜营养不良一家系基因研究

摘要

目的 对Avellino角膜营养不良一家系进行分子遗传学分析及分类,了解其转化生长因子β诱导(TGFBI)基因突变的类型.方法 收集 1个Avellino角膜营养不良家系中的4例患者,2例表型正常成员和100例正常对照者的外周血5 ml,提取DNA后利用TGFBI基因所有17个外显子的特异性引物,进行聚合酶链反应(PCR)扩增,并对PCR产物行DNA测序分析.结果 该家系4例患者的TGFBI基因第4号外显子存在CGC>CAC(R124H)杂合突变,而家系表现正常成员无此基因位点突变.同时4例患病家庭成员存在同义单核苷酸多态性 rn(SNP):第 11外显子杂合性的CTC>CTT(L472L),第 12外显子杂合性的 TTT>TTC (F540F) 结论 Avellino角膜营养不良家系存在TGFBI基因突变,为R124H杂合突变类型.%Objective To detect and classify the mutation of transforming growth factor beta-induced( TGFBI) gene in a Chinese family with Avellino corneal dystrophy and identify the type of gene mutation. Methods Peripheral blood was sampled from 4 patients with Avellino corneal dystrophy, 2 unaffected family members and 100 normal control were subjected to extract DNA. All of the 17 exons of the TGFBI gene were amplified by polymerase chain reaction ( PCR ), and the amplified products were sequenced and compared the sequence with GenBank. Results Direct sequencing of all affected members revealed at exon 4 a G to A transition at codon ( CGC to CAC ), All affected members at exon 11 possess a C to T transition at codon CTC to CTT ( L472L ) and exon 12 has a T to C transition at codon TTT to TTC ( F540F ). Conclusion This Chinese family is found to have R124H mutation of the TGFBI gene validated as Avellino corneal dystrophy.