一个角膜炎-鱼鳞病-耳聋综合征家系的致病突变分析

Mutation analysis for a pedigree affected with keratitis-ichthyosis-deafness syndrome

目的对1例角膜炎-鱼鳞病-耳聋综合征患者进行GJB2基因的突变鉴定，并在此基础上完成家系突变验证和突变起源分析。方法通过酚氯仿法提取基因组DNA；应用PCR-Sanger测序鉴定先证者GJB2基因外显子及外显子／内含子衔接区序列；针对先证者携带的突变位点，应用PCR-高分辨熔解曲线（high resolution melting，HRM）方法进行家系突变验证；利用T-克隆测序技术进一步确定突变的亲本来源。结果在先证者GJB2基因的第2外显子检测到1个C．148G）A（P．Asp50Asn）杂合错义突变，HRM分析结果与测序结果一致；克隆测序显示患儿致病突变源自父亲生殖细胞突变。结论在t个中国人角膜炎-鱼鳞病-耳聋综合征家系检测到GJB2基因热点突变e．148G〉A，并针对该突变建立一种基于PCR-HRM技术快速攀定突变的方法；此方法方便、怏捷，可作为该病患者突变筛杏的优选方法。

Objective To identify mutation of GJB2 gene and provide genetic counseling for a family affected with keratitis-ichthyosis-deafness （KID） syndrome. Methods Genomic DNA was extracted from peripheral blood samples with a standard phenol-chloroform method. PCR and Sanger sequencing were used to analyze potential mutation in the proband. Suspected mutation was verified with a PCR-high-resolution melting （PCR-HRM） method. T-clone sequencing was applied to determine the parental origin of the mutation. Results A heterozygous mutation, c. 148G〉A （p. AspSOAsn）, which is located in the exon 1 of the GJB2 gene, was found in the proband. The results was confirmed by HRM analysis. Cloning sequencing suggested that the mutation was derived from the father＇s germline. Conclusion The hot-spot mutation c. 148G〉A （p. AspSOAsn） in the GJB2 gene probably underlies the KID syndrome in this Chinese family. A PCR-HRM method has been established to rapidly detect common mutations associated with this disease.