Novel Mutations Resulting in a Moderate to Severe Phenotypic Manifestation of Hemophilia A in a Female.

Hemophilia A is an X-linked, recessive disorder resulting from mutations in the f8 gene. Here we report the rare case of a female compound heterozygote with mild factor VIII deficiency (fVIII:C 9%) and moderate phenotype. On investigation she was confirmed to have normal Von Willebrand factor studies with a 46XY genotype. Further genetic testing revealed 3 mutations in the f8 gene: 1 novel missense mutation (c.6142T>G), 1 novel in-frame deletion (c.1281_1292del), and another missense mutation of unclear significance (c.3780C>G). Both parents had normal coagulation profiles; however, the 2 novel mutations were present in the patient's mother and the known missense mutation was present in her father. This unusual case demonstrates the utility in genetic analysis for f8 gene mutational analysis and suggests a compound effect of the 3 identified mutations as a cause for factor deficiency.