IMEX   05356
INSTITUTO DE MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PO636-TUE VWD2B phenotype: its prevalence within families and bleeding tendency in affected members
Autor/es:
WOODS AI; KEMPFER AC; PAIVA-PALOMINO J; BERMEJO EI; BLANCO AN; CHUIT R; SÁNCHEZ LUCEROS A; LAZZARI MA
Lugar:
Toronto
Reunión:
Congreso; XXV Congress of the International Society on Thrombosis and Haemostasis and 61st Annual SSC Meeting.; 2015
Institución organizadora:
International Society on Thrombosis and Haemostasis
Resumen:
Background: von Willebrand disease type 2B (VWD2B) is characterized by gain-of function mutations (Mt), low platelet count (PC), ristocetin induced platelet aggregation at low concentration (RIPA).Aims: To correlate bleeding tendency in affected members (AFM) in families (F), and also determine Mt penetrance and VWD prevalence (Pr) in F with ≥ 2 generations (G).Methods: We have 12F, with 36M (AFM=28). Bleeding score (BS), major bleeding (MB), PC (9109/L), bleeding time (BT)(min), VWF (IU/dL), lower RIPA concentration (mg/mL), VWFpp/VWF:Ag (VWFpp).Results: Following Mt were described: p.R1304V: atypical VWD2B= 1F; n= 3; 2G; AFM=3; AFM with: abnormal BS=66.6%, both normal PC and multimers=100%, RIPA 0.4 = 33.4%, 0.5= 66.6%, MB= 33.3%.BT=7.7; VWF:Ag = 24 6.7; VWF: RCo = 27 12; RCo/Ag = 1.1 0.2; VWFpp = 2.5 0.3 (normal value=1.5 0.6); PC=192 26.Pr=100%. p.R1306W = 2F; n = 6; 3G; AFM = 5; AFM with abnormal BS = 100%, low PC and absence HMWM = 100%, RIPA 0.5 = 66.6%, 0.7 = 33.3%, MB = 60%.BT = 7.2 1; VWF:Ag=53 14; VWF:RCo=43 16; RCo/Ag=0.8 0.2; VWFpp=2.2 1.5; PC=90 41.Pr=83.3%. p.R1308C = 4F; n = 8; 2G; AFM = 7; AFM with abnormal BS = 28.6%, low PC = 29%, absent HMWM = 100%, RIPA0.3 = 33.3%, 0.4 = 16.6%, 0.6 =16.6%, 0.7 = 33.3%, MB = 28.6%. BT = 10 2; VWF: Ag = 54 21; VWF:RCo = 12 5.4;RCo/Ag = 0.2 0.1; VWFpp = 2 0.6; PC = 161 76.Pr = 100%. p.S1310F = 1F; n = 5; 2G; AFM = 3; AFM with abnormal BS = 100%, low PC and absent HMWM = 100%, RIPA0.4 = 66.6%, 0.7 = 33.4%, MB = 66.6%.T =not done; VWF:Ag = 66 19; VWF:RCo=52 17; RCo/Ag=0.8 0.1; VWFpp = 2.1 0.2; PC = 66 63. Pr=100%. Parents withoutMt: probable de novo in all AFM. p.V1316M = 4F; n = 14; 3G; AFM = 10; AFM with abnormal BS = 100%, low PC = 70%, absent HMWM = 100%, RIPA0.3 = 37.5%, 0.5 = 50%, 0.7 = 12.5%, MB = 60%.BT = 11 3; VWF:Ag = 51 20; VWF:RCo = 28 12; RCo/Ag = 0.5 0.2; VWFpp = 2.0 0.7; PC = 119 108.Pr=77.8%. Parents without Mt: probable de novo in the AFM of one F.Conclusion: A 45% of AFM showed VWFRCo/VWFAg > 0.6. MB was related to PC: P = 0.034; likelihood ratio of +test=2.7; RR=2.66. Presence of Mt in all G (complete penetrance) makes mandatory family study. Similar prevalence of VWD2B was seen in all F. Low PC showed to be a risk factor of MB in VWD2B