FVIII coagulant (FVIII: C) activity was measured on citrated plasma samples from these patients by one-stage APTT method while FV coagulant activity was measured by a PT based method. From 1998 till 2001, the factor assay was done by Coag-a-mate; RA4 (Organon Teknika), from 2001 till 2006 by CA-1500 Sysmex coagulometer (Sysmex, Hyogo, Japan) and from 2006 onwards by ACL Advance (Beckman Coulter). For the diagnosis of combined FV and VIII deficiency, the cut-off values for FV (<40%) and FVIII: C (<45%) was considered as previously described [7] .