Trapped neutrophil syndrome
The disease, which is similar to Cohen syndrome in humans, is caused by a mutation in the canine VPS13B gene and was originally described in the Australian and New Zealand population of Border collies characterised by a deficiency of segmented neutrophils in the blood and hyperplasia of myeloid cells in the bone marrow.
This syndrome has been traced back to a single common ancestor suggesting that the disease was the result of a single mutational event that had been spread through the population by the champion sire effect. If the mutation predates development of the breed it may exist in other collie breeds, as does Collie eye anomaly.
Severely affected pups show abnormal craniofacial development with a narrowed elongated skull shape described by breeders as ferret-like. Affected pups are often smaller than their litter mates and suffer from chronic infections and failure to thrive resulting from a compromised immune system as well as varying degrees of mental retardation.
Some show early infections from six weeks of age. For others the first sign of TNS is a bad reaction to immunisation at 12 weeks, while in a few cases clinical signs are very mild and not recognised until two or more years of age.
A PCR-based assay is currently available for this disease.
Many dogs succumb to the disease at an early age.
- Mizukami K et al (2012) Trapped neutrophil syndrome in a Border Collie dog: clinical, clinico-pathologic, and molecular findings. J Vet Med Sci 74(6):797-800
- Allan, FJ et al (1996) Neutropenia with a probable hereditary basis in Border Collies. N Z Vet J 44:67–72
- Shearman JR et al (2006) Exclusion of CXCR4 as the cause of Trapped Neutrophil Syndrome in Border collies using five microsatellites on canine chromosome 19. Anim Genet '37:89
- Parker HG et al (2007) Breed relationships facilitate fine-mapping studies: a 7.8-kb deletion cosegregates with Collie eye anomaly across multiple dog breeds. Genome Res 17:1562–1571
- Shearman JR & Wilton AN (2007) Elimination of neutrophil elastase and adaptor protein complex 3 subunit genes as the cause of trapped neutrophil syndrome in Border collies. Anim Genet 38:188–189
- Shearman JR et al (2011) A canine model of Cohen syndrome: Trapped Neutrophil Syndrome. BMC Genomics 12:258