Hemophilia carrier status and counseling the symptomatic and asymptomatic adolescent

Carriers of hemophilia have a 50% chance of giving birth to a hemophilic son. Approximately 35% may have a lower than normal factor VIII or IX and therefore can be diagnosed without genetic testing. These individuals may present with menorrhagia, menometrorrhagia and dysmenorrhoea. The treatment of menorrhagia is similar to girls without bleeding disorders--tranexamic acid, the oral contraceptive pill and, where acceptable, the levonorgestrel-releasing intrauterine device. Genetic diagnosis is possible for potential carriers--50% families with severe hemophilia carry the intron 22 inversion and databases are available which list most of the causative mutations for hemophilia A and B. Ideally the mutation in the index in a family is known. The testing of adolescents for a recessively inherited condition raises ethical issues and guidance may vary within different countries and cultures.