MUTATION REPORTType II antithrombin deficiency caused by a novel missense mutation (p.Leu417Gln) in a Chinese familyLiu, Siqi; Wang, Huanhuan; Xu, Qiyu; Luo, Shasha; Jin, Yanhui; Yang, Lihong; Wang, MingshanAuthor Information Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China Correspondence to Mingshan Wang, MM, Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China Tel: +86 57788069594; fax: +86 57788069596; e-mail: [email protected] Received 20 June, 2020 Accepted 11 October, 2020 Blood Coagulation & Fibrinolysis: January 2021 - Volume 32 - Issue 1 - p 57-63 doi: 10.1097/MBC.0000000000000973 Buy Metrics Abstract The aim of the report was t o explore the phenotype and genotype of a hereditary antithrombin deficient Chinese family. Functional and molecular analysis of the proband and his family members was performed. Online bioinformatics software was used to predict the pathogenicity of the novel mutation. ClustalX-2.1-win and PyMol software were applied to conservative analysis and generate molecular graphic images, respectively. Functional analysis had shown that the antithrombin (AT):A of the proband was reduced to 32% whereas AT:Ag was normal. Molecular analysis revealed a heterozygous missense mutation p. Leu417Gln in exon 7 of SERPINC1 gene. Bioinformatics and model analysis indicated that this mutation could affect the integrity of local intermolecular structures, resulting in a mild type of antithrombin deficiency but when combined with other genetic or acquired thrombophilic factors, patients may develop venous thrombosis. The p.Leu417Gln mutation was responsible for the decrease of AT:A in this family and caused type II antithrombin deficiency. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.