Hemophilia: a practical approach to genetic testing.

Hemophilia and von Willebrand disease together account for the large majority of congenital bleeding disorders. Contemporary management, including development of safer clotting factor concentrates and increased emphasis on long-term follow-up in comprehensive hemophilia centers, has improved both quality of life and longevity for patients with congenital bleeding disorders. In addition to facilitating development of recombinant clotting factor concentrates, isolation and characterization of the respective genes have led to increasing availability of a repertoire of genetic tests that, although expensive, are critical for appropriate genetic counseling of affected patients and their family members. This article provides a practical approach to using genetic testing for hemophilia A and B.