摘要
目的 通过对广西地区一个毛发-肝脏-神经发育综合征家系进行临床表型分析和基因突变分析,揭示其分子致病机制,为该家系进行遗传咨询提供依据。方法 在广西壮族自治区妇幼保健院对患者进行临床表型分析,采集外周血并送往北京全谱医学检验实验室提取DNA外显子测序进行基因突变筛查;对患者进行家系分析及采集家系成员外周血,然后通过生工生物进行Sanger测序验证;在南方医科大学医学遗传实验室进行以下功能实验:基于pEGFP-C1载体,使用EcoRI和BamHI构建含CCDC47的野生型质粒及含CCDC47 c.634C>T(p.Arg212*)的突变质粒;用脂质体法将以上质粒分别转染HEK293T细胞;利用荧光定量PCR技术和Western blotting对突变CCDC47基因mRNA和蛋白进行检测分析;用免疫荧光检测突变蛋白亚细胞定位变化;用I-TASSER预测蛋白质三级结构的变化。结果 患者CCDC47基因第5外显子存在纯合突变c.634C>T(p.Arg212*),其父母和两个姐姐均为该突变的携带者。该突变导致产生一个截短蛋白,与野生型相比,CCDC47基因突变前后蛋白的细胞定位无差异,但该突变导致CCDC47的mRNA和蛋白表达降低,蛋白三维结构发生明显改变。结论 本文报道了1例由CCDC47基因新突变c.634C>T(p.Arg212*)导致毛发-肝脏-神经发育综合征发生,该突变蛋白结构发生显著改变及表达下降可能是导致该病发生的致病原因。研究扩展了CCDC47基因的突变图谱,为THNS患者的早期诊断与该家系遗传咨询提供了重要依据。
Objective To elucidate the molecular pathogenic mechanism by analyzing the clinical phenotype and genetic mutations in a family with trichothiohepatoenteric syndrome(THNS)from Guangxi,China,and to provide a basis for genetic counseling for the family.Methods Clinical phenotype analysis was performed on the patient at the Guangxi Maternal and Child Health Hospital.Peripheral blood was collected and sent to Beijing Quanpu Medical Laboratory for DNA extraction and exome sequencing to screen for genetic mutations.Family analysis was performed,and peripheral blood samples were collected from family members.Sanger sequencing verification was performed at Sangon Biotech.The following functional experiments were conducted in the Medical Genetics Laboratory of Southern Medical University:Using the pEGFP-C1 vector and restriction enzymes EcoRI and BamHI,wild-type plasmids containing CCDC47 and mutant plasmids containing the CCDC47 c.634C>T(p.Arg212*)variant were constructed.The constructed plasmids were transfected into HEK293T cells using the lipofection method.Quantitative real-time PCR and Western blotting were used to analyze mRNA and protein expression of the mutant CCDC47 gene.Immunofluorescence was employed to investigate the changes in the subcellular localization of the mutant protein,and the I-TASSER tool were used to predict alterations in the protein's tertiary structure.Results A homozygous mutation(c.634C>T,p.Arg212*)in exon 5 of the CCDC47 gene was identified in the proband,Both parents and two elder sisters were heterozygous carriers of this mutation.Compared to the wild-type,the mutant CCDC47 protein showed no significant difference in subcellular localization but exhibited markedly reduced mRNA and protein expression,along with significant structural changes in its three-dimensional conformation.Conclusion This study reports a novel CCDC47 mutation(c.634C>T,p.Arg212*)causing THNS,likely due to the substantial structural alteration and decreased expression of the mutant protein.The findings expand the mutational spectrum of the CCDC47 gene and provide critical insights for the early diagnosis of THNS and genetic counseling for the affected family.
作者
钟为军
刘佳楠
熊符
何菲
ZHONG Weijun;LIU Jianan;XIONG Fu;HE Fei(Department of Medical Genetics,School of Basic Medical Sciences,Southern Medical University,Guangzhou 510515,China)
出处
《分子影像学杂志》
2025年第9期1168-1173,共6页
Journal of Molecular Imaging
基金
国家自然科学基金项目(32570722),国家自然科学基金青年项目(82302078),广东省基础与应用基础研究基金项目(2022A1515110438)
