Mutation Causing von Willebrand's Disease in Scottish Terriers
Patrick J. Venta, Jianping Li, Vilma Yuzbasiyan-Gurkan, George J. Brewer, and William D. Schall
Von Willebrand’s Disease (vWD) in the Scottish Terrier breed is
a serious, often fatal, hereditary bleeding disorder. Elimination of the
mutated gene by selective breeding is an important goal for the health
of this breed. Although the standard protein-based tests are accurate for
identification of affected Scottish Terriers, they are not reliable for
the identification of carriers of the mutant gene unless multiple replicate
assays are performed. A simple, highly accurate test for carriers of the
disease is needed so that veterinarians can counsel clients on which animals
to use in their breeding programs. The complete coding region of von Willebrand
factor (vWF) complementary DNA (cDNA) was sequenced from an affected animal,
and a single base deletion in the codon for amino acid 85 of the prepro-vWF
cDNA that leads to Scottish Terrier vWD was identified. A highly accurate
polymerase chain reaction assay was developed that can distinguish homozygous
normal animals from those that are homozygous affected or heterozygous.
In a voluntary survey of 87 animals provided by Scottish Terrier owners,
15 were carriers and 4 were affected with vWD, 2 of which had previously
been shown to have undetectable vWF. The determination of the complete
canine vWF cDNA sequence should facilitate the identification of additional
vWD alleles in other breeds and other species.
Keywords: Bleeding disorder, Deletion, Dog, Genetic disease
©
2000, American College of Veterinary Internal Medicine
top
