Investigation of a hemophilia family with one female hemophilia A patient and 12 male hemophilia A patients

Hemophilia A (HA) is an X-chromosome-linked recessive genetic disorder. Female carriers may have bleeding symptoms, but rarely have moderate or severe disease. We identified a female patient with moderate HA by pedigree tracking and genetic testing in a HA family involving consanguineous marriage. To investigate the clinical and laboratory data, as well as F8 genetic variant affecting members in her family. We constructed a detailed pedigree diagram and performed coagulation analyses, including factor VIII activity (FVIII:C), FVIII inhibitor, and von Willebrand factor antigen (VWF: Ag) on 20 family members. The genomic DNA of 11 members was screened for intron 1 and intron 22 inversions using long-distance real-time polymerase chain reaction (RT-PCR). Their F8 coding genes were sequenced with an automatic next-generation sequencing. Thirteen HA persons with hemophilia (12 males, one female) and 18 female carriers were identified in the family. VWF: Ag level was normal in all 13 persons with hemophilia and 7 carriers tested. The female HA patient had FVIII:C 1.9 IU/dL and was homozygous for F8:c.1918G > T:p.V640F. Genetic testing is conducive to the diagnosis of hemophilia carriers and persons with hemophilia. F8: c.1918G > T:p.V640F is the pathogenic HA variant in this family. In any hemophilia family, we need to pay more attention to female carriers and patients.