Mutation causing von Willebrand's disease in Scottish Terriers.

Area of Science:

• Genetics
• Veterinary Medicine
• Canine Health

Background:

• Von Willebrand's Disease (vWD) is a severe, often fatal, hereditary bleeding disorder in Scottish Terriers.
• Selective breeding is crucial for eliminating the mutated gene responsible for vWD.
• Current protein-based tests are unreliable for identifying vWD carriers.

Purpose of the Study:

• To develop a simple, highly accurate genetic test for identifying vWD carriers in Scottish Terriers.
• To enable veterinarians to better counsel breeders on managing vWD in their programs.
• To identify the specific genetic mutation causing vWD in this breed.

Main Methods:

• Sequencing the complete coding region of von Willebrand factor (vWF) complementary DNA (cDNA) from affected dogs.
• Identifying a single base deletion mutation in the prepro-vWF cDNA.
• Developing a polymerase chain reaction (PCR) assay to distinguish between normal, carrier, and affected animals.

Main Results:

• A single base deletion at amino acid 85 of the prepro-vWF cDNA was identified as the cause of vWD in Scottish Terriers.
• The developed PCR assay accurately differentiated homozygous normal, heterozygous carrier, and homozygous affected dogs.
• A survey of 87 Scottish Terriers revealed 15 carriers and 4 affected dogs, including two previously undetected cases.

Conclusions:

• The new PCR assay provides a highly accurate method for identifying vWD carriers in Scottish Terriers.
• This genetic test facilitates selective breeding strategies to reduce the incidence of vWD.
• The canine vWF cDNA sequence can aid in identifying vWD in other breeds and species.