The natural history of mild haemophilia: a 30-year single centre experience.

Although up to 50% of all haemophilic patients followed at haemophilia treatment centres (HTCs) are affected by a mild factor VIII (FVIII) or factor IX (FIX) defect, published data regarding the natural history of these disorders are scarce. To fill this lack of information, a retrospective single centre study was conducted. All cases with mild haemophilia (75 A and 7 B) followed at the regional reference HTC of Parma were evaluated. The patients' median age at diagnosis was 11.5 years and their median age at first bleeding was 5.5 years; 95% of patients had a history of haemorrhagic problems during their life. Twenty-three percent of patients were infected by HCV, and none by HIV. Genetic analysis was performed in 80 patients (97% haemophilia A and 100% haemophilia B) and 21 different mutations were characterized. Eleven percent of patients had never received treatment, whereas 67% were treated with plasma-derived or recombinant FVIII/FIX concentrates (4% developed inhibitors). desmopressin (DDAVP) was used in 80% of the haemophilia A patients. The response to DDAVP was closely related to the patients' genetic profile, as 60% of non-responders had a mutation in the F8 promoter region. Patients with mild haemophilia may experience a variety of medical problems, sometimes challenging for the physicians, during their lifetime. The HTCs play an important role in the management of these patients, whose diagnosis is often delayed. The HTCs should improve patients' knowledge and consideration of their disease and encourage them to maintain regular contact with their haemophilia care provider.