Genetic basis of Dermatomyositis - is a complex autoimmune disorder with a strong genetic association to alleles in the HLA-DRB1 region, particularly the DRB103:01* or DLA-DRB1002:01* risk alleles. The risk alleles are part of the extended HLA 8.1 ancestral haplotype, which confers a substantially increased risk for DM and other idiopathic inflammatory myopathies in both humans and dogs. In dog genetics, this risk allele is sometimes denoted as “C” for DLA-DRB1*002:01; other risk alleles for canine DM may also include “A” and “B” depending on the assay and breed. Genetic testing of these alleles helps identify individuals at low, moderate, or high risk depending on their genotype, with uppercase letters in genotype reports representing risk alleles and lowercase representing “wild-type” or normal alleles

Pathophysiology - is characterized by immune-mediated inflammation of the skin and muscles, resulting in skin lesions and progressive muscle weakness. The disease mechanism involves the body’s immune system targeting tissues expressing particular HLA-DRB1 variants, with additional environmental triggers possibly required for disease onset. The presence of certain risk alleles is associated with both earlier onset and more severe disease presentations.

Complications - can cause chronic skin ulcers, muscle wasting, difficulty eating or swallowing, and reduced mobility. Scarring and secondary infections may occur. Severely affected dogs may have a diminished quality of life and require ongoing medical or supportive care. The disorder can be progressive and, in some cases, fatal if muscle and skin involvement become severe

Why This Matters to Breeders and Vets - Breeders can use genetic testing to plan matings that minimize risk, protecting future generations from this painful and potentially debilitating disease. Veterinarians can identify at-risk dogs before symptoms appear, advise owners, and tailor monitoring and management strategies for dogs at moderate or high genetic risk. Early detection through genetic testing allows for better disease surveillance, targeted preventive strategies, and improved client education.

Our single test processing service provides comprehensive and reliable testing for a variety of sample types, including cheek swab, blood or tissue samples. Each sample undergoes a meticulous testing process to deliver accurate results. These tests are excluded from the Turnaround Time Guarantee.

• Blood Samples: Collected in EDTA tubes by a licensed veterinarian to ensure high-quality DNA extraction and optimal test accuracy.
• Tissue Samples or Biopsies: Collected by a licensed veterinarian and stored in ethanol to preserve the sample for advanced testing purposes, ensuring flexibility and reliability for specialised testing needs.

These tests and sample types are specifically required as they are conducted as single stand-alone tests. Due to their scientific complexity and the need for precise methodologies, they are processed independently to ensure the highest accuracy and reliability. This service is ideal for veterinarians, breeders, and pet owners seeking insights into a specific genetic condition or trait, while meeting the stringent requirements for these advanced, complex tests.