VWF and von Willebrand disease 2: In type 2 vWD there are typical VWF regions, where mutations cause well-defined phenotypes, like exon 28 mutations, which are responsible for 2A, 2B and 2M, mutations in exons 11–16, 24–26 and 51–52 leading to 2A, exon 18–25 mutations associate with 2N phenotype.