内科

目的探讨2个血管性血友病（von Willebrand Disease，VWD）家系的临床表型与血小板膜糖蛋白GP1BA（platelet glycoprotein Ib alpha，GPⅠba）、血管性血友病因子（von Willebrand factor，vWF）第28个外显子、血管性血友病因子裂解酶ADAMTS13基因变异情况。探索血管性血友病家系的发病机制。方法对4例临床诊断为血管性血友病家系的患者的外周血进行全基因组DNA提取，参照CCDS数据库人类基因序列设计PCR引物，以基因组DNA为模板对GP1BA、vWF28、ADAMTS13基因进行PCR扩增后采用凝胶电泳观察产物是否合格并进行基因测序。结果在一个家系中发现GP1BA基因G1206A（E429K）突变位点，同时检出一父子存在39个碱基缺失但不是VNTR序列，且发现该患儿母亲GP 1BA存在VNTR B/C杂合子。检测到vWF 28多态性位点G4039A（SNP位点）、A4391G（T1381A）、G4664C（D1472H）、T4891C（SNP位点）；2个家系的ADAMTS13基因均未发现突变位点。结论（1）在vWF28上发现多态性位点G4039A（SNP位点）、A4391G（T1381A）、G4664C（D1472H）、T4891C（SNP位点），可能与家系1（2B型血管性血友病）的发病有关。（2）在家系2中，患者的GP1BA基因上检测到一个新的突变位点G1206A（E429K），可能与患者患有血小板型血管性血友病有关。（3）本研究还发现在家系2中患者及患者的父亲GP1BA基因均存在一段39个碱基的缺失，但并不是串联重复序列（Variable Number of Tandem Repeats，VNTR）片段。且患者的母亲存在VNTR B/C杂合子。可能是促进该患者发病的重要因素。

【Abstract】ObjectiveTo study the clinical phenotype in two Chinese Pedigrees with VWD of GP1BA、vWF28、ADAMTS13 gene sequences, and explore the mechanism of VWD. MethodsThe blood genomewide DNA of 4 patients who diagnosed as VWD with peripheral was extracted, the GP1BA、vWF28、ADAMTS13 gene were amplified with PCR and analyzed by gel electrophoresis and direct sequencing, PCR primer was designed based on database of gene sequences of CCDS databases and genomic DNA was used as a template for PCR amplification. ResultsThe novel mutation of G1206A (E429k) of GP1BA gene was found in one pedigree and showed a VNTR B/C heterozygote in GP1BA gene, and a male patient and his father showed a deletion of 39 bases rather than a VNTR, and VNTR B/C heterozygote was found in GP1BA of his mother. In addition, several polymorphisms in exon 28 of vWF gene were identified, including G4039A, A4391G, G4664C, and T4891C. There was no genetic variant found in the ADAMTS13 gene. Conclusions(1) The polymorphisms of G4039A, A4391G, G4664C, and T4891C in exon 28 of vWF gene may contribute to the pathogenesis of 2B VWD. (2) A new genetic mutation G1206A（E429K）is tested in GP1BA patients′ gene in Chinese pedigrees 2, this may be connected with PTVWD of patients. (3) Furthermore, there are deletions of 39 bases in patient and his father′s gene in Chinese pedigrees 2 of this research, which are not the variable number of tandem repeats. Besides, there is VNTR B/C heterozygote in patient’s mother, this may contribute to the pathogenesis of 2B VWD.