Cheng X L, Yang T, Yang L, Xin Y J, He M, Zhu L, Liu J Y
Department of Clinical Laboratory, the First Affiliated Hospital of Air Force Medical University, Xi'an 710032, China.
Department of Clinical Laboratory, the Quzhou Affiliated Hospital (Quzhou People's Hospital) of Wenzhou Medical University, Quzhou 324000, China.
Zhonghua Yi Xue Za Zhi. 2023 May 9;103(17):1323-1327. doi: 10.3760/cma.j.cn112137-20220828-01821.
To analyze the gene variation of a genetic coagulation factor Ⅴ (FⅤ) deficiency pedigree and explore the molecular pathogenesis. The proband was a 32 years old female. The patient was prone to nose bleeding since childhood which was usually self-healed. On March 10, 2021, the proband went to the First Affiliated Hospital of Air Force Medical University for treatment of knee hematoma caused by a fall. None of the family members reported any history of bleeding. The prothrombin time (PT), activated partial thromboplastin time (APTT) and FⅤ activity (FⅤ: C) were detected by clotting method and the FⅤ antigen (FⅤ: Ag) was tested with enzyme-linked immunosorbent assay (ELISA). All exons and flanks of F5 gene were determined by Sanger sequencing. Clustalx-2.1-win, PolyPhen-2 and Swiss-PDBViewer software were used to analyze the conservatism of missense variation sites, whether the variations were harmful and their influences on protein structure and function. MutationTaster and NetGene2 software were used to analyze whether the splice site variation was harmful and its effect on the splice site. The PT and APTT of the proband prolonged to 24.0 s and 69.8 s, respectively. The FⅤ: C and FⅤ: Ag decreased to 6% and 9%, respectively. There were compound heterozygous variations in F5 gene, which included c.911G>A heterozygous missense variation in exon 6 leading to p.Gly276Glu variation and c.5208+1G>A heterozygous missense variation in intron 15. The father and daughter had the p.Gly276Glu heterozygous variation. Her mother and son had the c.5208+1G>A heterozygous variation. Software analysis results of p.Gly276Glu heterozygous variation showed that Gly276 was conserved among homologous species, the variation was harmful, and it could affect the local structure and function of the protein. The c.5208+1G>A heterozygous variation was deleterious and resulted in the disappearance of the splice site, thereby affecting the protein function. The p.Gly276Glu and c.5208+1G>A compound heterozygous variants are deleterious variants associated with the patient's disease and may be the molecular pathogenesis of inherited FⅤ deficiency in this family.
分析遗传性凝血因子Ⅴ（FⅤ）缺乏症家系的基因变异，探讨其分子发病机制。先证者为一名32岁女性。患者自幼易鼻出血，通常可自愈。2021年3月10日，先证者因跌倒致膝关节血肿前往空军军医大学第一附属医院就诊。家族成员均无出血史。采用凝固法检测凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）及FⅤ活性（FⅤ：C），用酶联免疫吸附试验（ELISA）检测FⅤ抗原（FⅤ：Ag）。采用Sanger测序法测定F5基因的所有外显子及其侧翼序列。运用Clustalx - 2.1 - win、PolyPhen - 2及Swiss - PDBViewer软件分析错义变异位点的保守性、变异是否有害及其对蛋白质结构和功能的影响。使用MutationTaster和NetGene2软件分析剪接位点变异是否有害及其对剪接位点的影响。先证者的PT和APTT分别延长至24.0秒和69.8秒。FⅤ：C和FⅤ：Ag分别降至6%和9%。F5基因存在复合杂合变异，包括外显子6中的c.911G>A杂合错义变异，导致p.Gly276Glu变异，以及内含子15中的c.5208 + 1G>A杂合错义变异。父亲和女儿携带p.Gly276Glu杂合变异。她的母亲和儿子携带c.5208 + 1G>A杂合变异。p.Gly276Glu杂合变异的软件分析结果显示，Gly276在同源物种中保守，该变异有害，可影响蛋白质的局部结构和功能。c.5208 + 1G>A杂合变异有害，导致剪接位点消失，从而影响蛋白质功能。p.Gly276Glu和c.5208 + 1G>A复合杂合变异是与患者疾病相关的有害变异，可能是该家族遗传性FⅤ缺乏症的分子发病机制。
