A case of factor XI deficiency gene mutation and clinical analysis

Objective To conduct gene mutation detection in a proband with coagulation factor XI (FXI) deficiency, preliminarily explore its pathogenesis, and enrich the FXI deficiency database. Methods Use a coagulometer to test each coagulation index to determine the coagulation factors that need to be focused; use the high-throughput next generation sequencing technology based on liquid phase capture technology (Next Generation Sequencing) to detect coagulation factor XI (FXI) related gene F11 extragene For intron regions, intron mutations within 20 bp of upstream and downstream, and insertion/deletion (indel) mutations of less than 50 bp, use the results of first-generation sequencing to verify the mutation site; use bioinformatics tools to predict the likelihood of the mutation site causing disease And whether the mutation affects protein function. Results The proband's activated partial thromboplastin time measurement (APTT) was significantly prolonged (74.6 seconds), the activity of coagulation factor XI was significantly decreased (4.1%), the sequencing result showed F11 gene mutation, and the mutation site was the 13th exon c.1550C>A/p.Thr 517Asn. Conclusion This mutation is a new mutation site of hereditary coagulation factor XI (FXI) deficiency, and this mutation is pathogenic.