Hemophilia A with reduced coagulation factor Ⅺ: a case report and literature review

Abstract

Objective To investigate the possible molecular pathogenesis of a child with hemophilia A accompanied by coagulation factor Ⅺ reduction by testing coagulation-related indicators and genotyping in the child and his family. Methods Peripheral blood from the patient and his parents for detection of coagulation factors Ⅷ, Ⅸ, Ⅺ, Ⅻ, VWF∶Ag, lupus anticoagulants and F VIII, F XI inhibitors were collected. All exons and flanking sequences of the genes encoding FⅧ and FⅪ were sequenced and bioinformatically analyzed. Results The child had low FⅧ and FⅪ activity and no parental abnormalities were observed. The sequencing results showed that there was a c. 1834(exon12) C>T heterozygous mutation in the FⅧ gene and a c. 1817 (exon15) G>A heterozygous mutation in the FⅪ gene, which was de novo. Bioinformatics analysis shows that the FⅪ mutation changes the original protein structure and increases the number of carboxyl groups. Conclusion For patients with prolonged APTT, in addition to excluding factors that interfere with APTT testing, all coagulation factors related to APTT should be tested to clarify the diagnosis.

Keywords

• factor ⅷ
• factor ⅺ
• gene mutation
• second-generation sequencing
• surgery