角膜炎、鱼鳞病、耳聋综合征一例及GJB2基因突变研究

目的 探讨角膜炎、鱼鳞病及耳聋综合征患者临床特征和GJB2基因突变情况，为该病临床与基因诊断提供依据。方法 收集1例角膜炎、鱼鳞病及耳聋综合征患者的临床资料，提取患者及家族成员的外周血DNA，用PCR扩增GJB2基因外显子2及其附近的剪切点，DNA直接测序法进行基因突变检测。结果 该患者存在血管化角膜炎、鱼鳞病及先天性耳聋三联征的典型临床特征，检测到GJB2基因中核苷酸序列外显子2第148位碱基由G突变为A，导致编码的连接蛋白Cx26第50位的天冬氨酸转换成天冬酰胺（D50N）。其未患病的母亲及哥哥未检测到突变位点。结论 GJB2基因突变（D50N）可能是引起鱼鳞病、角膜炎及耳聋综合征患者临床表型的原因。

Mutation analysis of GJB2 gene in a patient with keratitis-ichthyosis-deafness syndrome

Objective To investigate the clinical features of and GJB2 gene mutations in a Chinese Han patient with keratitis-ichthyosis-deafness syndrome （KID syndrome）, in hope to offer evidence for the clinical and genetic diagnosis of KID syndrome. Methods Clinical data were collected from a patient with KID syndrome. DNA was extracted from peripheral blood of the patient and his two family members （mother and brother）. PCR was performed to amplify the exon 2 and its flanking splicing sites of GJB2 gene followed by bidirectional direct DNA sequencing. Results The patient presented with the typical triad of vascularizing keratitis, ichthyosis and congenital deafness. A G148A mutation in the exon 2 of GJB2 gene, resulting in the substitution of aspartic acid by asparagine at position 50 of the junction protein connexin 26 （Cx26）, was identified in the patient, but not in either of his family members. Conclusion The G148A mutation in GJB2 gene may be responsible for the clinical phenotype of KID syndrome in this Chinese patient.