Analysis of a consanguineous pedigree affected with hereditary coagulation factor XII deficiency caused by homozygous Gly341Arg mutation

• Published in: Zhonghua yi xue yi chuan xue za zhi Vol. 35; no. 1; p. 69
• Main Authors: Yang, Lihong, Jin, Saiyan, Ji, Weidan, Cheng, Xiaoli, Li, Xiaolong, Jin, Yanhui, Wang, Mingshan
• Format: Journal Article
• Language: Chinese
• Published: China 10.02.2018
• ISSN: 1003-9406
• DOI: 10.3760/cma.j.issn.1003-9406.2018.01.015

OBJECTIVE To analyze the laboratory phenotype and FXII gene mutation in a consanguineous Chinese pedigree affected with factor XII (FXII) deficiency. METHODS Activated partial thromboplastin time (APTT), FXII activity (FXII:C) and FXII antigen (FXII:Ag) of the proband and her family members (10 individuals from 3 generations) were determined. Sanger sequencing was used to detect potential mutation within the 14 exons, their flanking regions and 5',3'-untranslated regions of the FXII gene. Suspected mutations were verified by backward sequencing. Conservation of the amino acids were analyzed with ClustalX-2.1-win. Four online bioinformatics software (PolyPhen-2, PROVEAN, SIFT and MutationTaster) were used to assess the impact of the mutations on the protein function. RESULTS The APTT of the proband and her elder brother have prolonged to 61.6 s and 68.6 s,and their FXII:C and FXII:Ag have decreased to 12%, 10% and 11%, 10%, respectively. The APTT of the paternal grandmother, maternal grandmother, father, mothe