Haematologica 2004;89: supplement no. 8 - Supplements ...

28Oral Communicationsstudy demonstrates the usefulness of a registry incollecting epidemiological data, health costs HRQoLand also to improve care delivered.CO-018PREVALENCE OF THROMBOPHILIC GENE MUTATIONS IN APOPULATION OF PATIENTS WITH INHERITED BLEEDINGDISORDERSCoppola A, Cimino E, De Simone C, Cirillo F,di Napoli F, Agnes R, Di Minno M, Tufano A,Di Minno GRegional Reference Centre for Coagulation Disease,Dep. of Clinical and Experimental Medicine;“Federico II” University, Naples, ItalyPhenotypic expression of inherited bleeding disordershas been thought to be affected by modifiergenes, able to mitigate their clinical severity. Amongthem, a role for thrombophilic gene mutations hasbeen proposed. We evaluated the prevalence of thewell defined thrombophilic mutations G1691A ofFactor V gene (FV Leiden) and G20210A of prothrombin(FII) gene in unrelated patients with severehemophilia (n=55) or von Willebrand disease (vWD,n=58, 41 women, 17 men) screened at our HemophiliaCentre. Prevalence of FV Leiden mutation was7.2% (4/55) in hemophiliacs and 1.7% (1/55) in vWDpatients, respectively. FII G20210A mutation wasdetected in 3.6% (2/55) of hemophiliacs and in 3.4%(2/58) of vWD patients (1 woman carried the homozygous20210A genotype). These gene frequencieswere comparable to those obtained in healthy subjectsfrom the same geographic and ethnic background(n=328, FV Leiden: 19/328, 5.8%; FIIG20210A: 17/328, 5.2%). On the whole, the 6 hemophiliacscarrying thrombophilic gene mutations didnot show clinical differences as far as severity or frequencyof bleeding episodes. Among the 3 vWDpatients with FV/FII mutations (all women), 2 had atype 1 disease with mild bleeding tendency; the thirdhad a more severe phenotype, with a long-lastinghistory of nose bleeding, but she had a type 3 disease.Three hemophiliac and 1 vWD patients had documentedatherosclerotic disease (1 coronary and 3peripheral artery disease): none carried thrombophilicgene abnormalities. A relatively low prevalenceof thrombophilic gene mutations is shown inthis population of patients with inherited bleedingdisorders. These data and the inherent limitations ofthe sample size make it difficult to define a possiblerole for thrombophilia in the phenotypic modulationof these diseases.CO-019A SKEWED X-INACTIVATION MECHANISM COULD EXPLAIN THESEVERE HEMOPHILIA B FEATURE OF A 3-YEAR OLD GIRL WITHA SEVERE HEMORRHAGIC DIATHESISMargaglione M, Schiavoni M,* Santacroce R,Di Perna P, Ettorre CP,* Ciavarella N*Genetica Medica Azienda Policlinico-Foggia, *U.O.S.Coagulazione-Med. Trasf. Azienda OspedalieraPoliclinico, Bari, ItalyHemophilia A and B are X-linked inherited hemorrhagicdiseases resulting from deficiencies of bloodcoagulation factor VIII or IX. Usually hemophilias aretransmitted by healthy heterozygous female carriersto affected males. Very rarely can a woman exhibithemophilia A or B and the most common explanationsfor how this can happen include compound heterozygosityand skewed X-inactivation. Few, isolatedcase-reports exist, so that we ignore the frequency ofhemophilia A and B in women and whether the clinicalphenotype is the same of that encountered inmales. Our experience regards a 3 year-old little girlsuffering from a severe hemorrhagic diathesis. Thefirst bleeding was an apparently spontaneoushemarthrosis of the left knee, afterward she presenteda large hematoma of left ilio-psoas muscle. Laboratorydata showed a prolonged PTT (R=1.97, n.v. 0.9-1.2) and the dosage of F.IX