Gastrointestinal angiodysplasia in a patient with type 2 von Willebrand's disease and analysis of exon 28 of the von Willebrand factor gene.

Although the association between gastrointestinal angiodysplasia and von Willebrand's disease has been suggested, molecular mechanisms involved in the formation of angiodysplasia in patients with von Willebrand's disease remained undetermined. We examined exon 28 of the von Willebrand factor gene in a patient with both von Willebrand's disease and recurrent bleeding from angiodysplasia in the duodenum as well as his father's, and found a point mutation, C 3916-->T (amino acid substitution; Arg 543-->Trp), in the A1 domain of the von Willebrand factor gene. This mutation was identical with a previously reported mutation in a patient with von Willebrand's disease complicated with gastrointestinal angiodysplasia.