A NOVEL MUTATION (LEU817PRO) CAUSING TYPE 2A VON-WILLEBRAND DISEASE

We studied a patient affected by von Willebrand disease type 2A who ex perienced several mild bleeding episodes and was characterized by mark edly reduced haemostatic parameters, In the exon 28 of von Willebrand factor (vWF) gene a T to C transition at nucleotide 8680, resulting in the missense mutation Leu817Pro, was found in the heterozygous form i n the patient and in two affected relatives, As suggested by the prese nce in platelets of a complete spectrum of vWF multimers as well as by the increased vWF antigen levels and improved haemostasis after DDAVP treatment, the mutation is compatible with normal multimerization, an d could be responsible for a reduced stability or an impaired physiolo gical secretion of vWF.