Other names: Von Willebrand disease II, VWDII
Affected Genes: VWF
Inheritance: Autosomal recessive
Mutations: CanFam3.1 27 g.38924099A>G c.4937A>G p.(N1646S)
CanFam3.1 27 g.38887211T>G c.1657T>G p.(W553G)
OMIA link: 001339-9615

Appropriate breeds for testing: German Shorthaired Pointer, German Wirehaired Pointer, Chinese Crested Dog

Symptoms :
Von Willebrand's disease causes a coagulation problem due to a deficiency of the von Willebrand factor protein necessary for the adhesion of blood platelets, resulting in prolonged provoked after injury. vWD disease is classified into three categories. Type I is the least severe with mild to moderate bleeding symptoms. Type II consists of vWF protein deficiency and moderate to severe defects. Type III is the most severe form of vWD.
Literature about type II von Willebrand disease (from the OMIA website)
Kramer et al. (2004) showed that a probable causative variant of this disorder in German Shorthaired Pointers is a base substitution in exon 28 of the VWF gene (c.4937A>G; p.Asn1646Ser).
Vos-Loohuis et al. (2017) reported that the most likely causative variant of this disorder in a German Wirehaired Pointer is another c.1657T>G mutation; p.Trp553Gly. They also reported and observed that only the c.1657G (p.553Gly) variation is found exclusively in the homozygous state in GWP and GSP dogs that are affected by VWD, and accordingly that this mutation is a primary candidate causative mutation. for sickness in races.
*** Depending on the laboratory, it is not always the same mutation that is tested for VWDII.
*** Betagene tests for both mutations i.e.: c.4937 A>G and c.1657 T>G

References:
Vos-Loohuis, M., van Oost, B.A., Dangel, C., Langbein-Detsch, I., Leegwater, P.A. A new variant of VWF associated with von Willebrand disease type 2 in German Wirehaired Pointers and German Shorthaired Pointers. Anim Genet 48:493-496, 2017. Pubmed reference: 28696025. DOI: 10.1111/age.12544.
Nichols, T.C., Hough, C., Agersø, H., Ezban, M., Lillicrap, D. Canine models of inherited bleeding disorders in the development of coagulation tests, new replacement proteins and gene therapies. J Thromb Haemost 14:894-905, 2016. Pubmed ID: 26924758. DOI: 10.1111/jth.13301.
Gavazza, A., Presciuttini, S., Keuper, H., Lubas, G. Estimated prevalence of canine Von Willebrand disease type 2 in the Deutsch-Drahthaar (German wirehaired pointer) in Europe. Res Vet Sci 93:1462-6, 2012. Pubmed ID: 22824509. DOI: 10.1016/j.rvsc.2012.06.010.
Burgess, H.J., Woods, J.P., Abrams-Ogg, A.C., Wood, R.D. Evaluation of laboratory methods to improve the characterization of dogs with von Willebrand disease. Can J Vet Res 73:252-259, 2009. Pubmed ID: 20046626.
Sabino, E.P., Erb, H.N., Catalfamo, J.L. Development of a collagen binding activity test as a screening test for type II von Willebrand disease in dogs. Am J Vet Res 67:242-9, 2006. Pubmed ID: 16454628. DOI: 10.2460/ajvr.67.2.242.
Kramer, JW., Venta, PJ., Klein, SR., Cao, Y., Schall, WD., Yuzbasiyan-Gurkan, V. Genomic nucleotide variant of von Willebrand factor A and polymerase chain reaction diagnostic test associated with hereditary type 2 von Willebrand disease in a line of German Shorthaired Pointers. Vet Pathol 41:221-8, 2004. Pubmed reference: 15133170. DOI: 10.1354/vp.41-3-221.