Congenital factor V deficiency from compound heterozygous mutations with a novel variant c.2426del (p.Pro809Hisfs∗2) in the F5 gene

Abstract Introduction: Congenital factor V deficiency (FVD) is a rare bleeding disorder characterized by low or undetectable plasma factor V (FV) levels leading to mild to severe bleeding symptoms. Currently, more than 100 mutations have been reported in F5 . We herein report a patient with FVD from mutations in the F5 gene. Patient concerns: A 52-year-old man with prolonged prothrombin time and activated partial thromboplastin time corrected by mixing test on preoperative screening. His past medical or family history was not remarkable. Diagnosis: Factor assays revealed a markedly reduced FV activity at 7%. Other factors were not decreased. DNA sequencing analysis to detect F5 gene mutations showed the patient was compound heterozygous for c.286G>C (p.Asp96His) and c.2426del (p.Pro809Hisfs∗2). Asp96His was previously described missense mutation and Pro809Hisfs∗2 was a novel deleterious mutation. Interventions: Fresh-frozen plasma was administered to supplement FV before surgery. Outcomes: Subsequent factor assays revealed temporarily increased FV activity at 33%. Conclusion: As was the case in our patient, genotype-phenotype correlations are poor in FVD, and molecular genetic test is necessary to confirm the diagnosis.