Jin Yanhui, Hao Xiuping, Cheng Xiaoli, Yang Lihong, Chen Yi, Xie Haixiao, Wang Yingyu, Wang Mingshan
Laboratory Medicine Center, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325015, China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2016 Jun;33(3):296-9. doi: 10.3760/cma.j.issn.1003-9406.2016.03.004.
To identify potential mutation underlying coagulation factor X (FX) deficiency in a consanguineous Chinese pedigree.
Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, FX activity (FX:C) and other coagulant parameters were determined with a one-stage clotting assay. The FX antigen (FX:Ag) was determined with an ELISA assay. All coding exons and exon-intron boundaries of the F10 gene were amplified with PCR and subjected to direct sequencing. Suspected mutation was confirmed by reverse sequencing and analyzed with CLC Genomics Workbench 7.5 software.
The PT and APTT in the proband were prolonged to 67.2 s and 102.9 s, respectively. Further study showed that her FX:C and FX:Ag were reduced by 1% and 8%, respectively. The PT of her father, mother, and little brother were slightly prolonged to 14.5 s, 14.4 s and 14.4 s, respectively. The FX:C and FX:Ag in her father, mother and little brother were all slightly reduced. Genetic analysis of the proband has revealed a homozygous G>A change at nucleotide 27881 in exon 8 of the F10 gene, which predicted a p.Val298Met substitution. The proband's father, mother, and little brother were all heterozygous for the p.Val298Met mutation. The proband has inherited the homozygous mutation from her parents by consanguineous marriage. Other family members were all normal. Bioinformatics analysis has indicated that this mutation may result in changes in the secondary structure of the FX protein.
A homozygous mutation g.27881G>A(p.Val298Met) of the F10 gene has been identified, which probably accounts for the low FX concentrations in this pedigree.
鉴定一个中国近亲家系中凝血因子X（FX）缺乏症潜在的突变。
采用一期凝血试验测定凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、纤维蛋白原、FX活性（FX:C）及其他凝血参数。用ELISA法测定FX抗原（FX:Ag）。通过PCR扩增F10基因的所有编码外显子和外显子-内含子边界，并进行直接测序。通过反向测序确认疑似突变，并使用CLC Genomics Workbench 7.5软件进行分析。
先证者的PT和APTT分别延长至67.2秒和102.9秒。进一步研究表明，她的FX:C和FX:Ag分别降低了1%和8%。她父亲、母亲和弟弟的PT分别轻度延长至14.5秒、14.4秒和14.4秒。她父亲、母亲和弟弟的FX:C和FX:Ag均略有降低。对先证者的基因分析显示，F10基因第8外显子核苷酸27881处存在纯合G>A变化，预测为p.Val298Met替代。先证者的父亲、母亲和弟弟均为p.Val298Met突变的杂合子。先证者通过近亲结婚从父母那里遗传了纯合突变。其他家庭成员均正常。生物信息学分析表明，该突变可能导致FX蛋白二级结构发生变化。
已鉴定出F10基因的纯合突变g.27881G>A（p.Val298Met），这可能是该家系中FX浓度低的原因。
