Breeds Affected: Border Collie
Samples Accepted: Blood, Buccal Swabs
Disease Information: Trapped Neutrophil Syndrome (TNS) is also known as Neutropenia or Cohen Syndrome. Affected pups may have an elongated “ferret shape” skull and be smaller than their littermates. Their immune system is compromised which may lead to chronic infections.
Inheritance Information: TNS is autosomal recessive, meaning that animals with two copies of this allele will be affected. Animals with one copy of the gene will be clinically-normal carriers.
The possible genotypes are:
N/N The dog is normal, and cannot produce affected offspring.
N/tns The dog is a carrier, and can pass the allele on to approximately 50% of any offspring. If bred to another N/tns carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.
tns/tns The dog is affected. If bred to a normal animal, 100% of the offspring will be carriers. If bred to a N/tns carrier, 50% of the offspring will be carriers and 50% will be affected.
– Carriers may be bred to normal animals (N/tns x N/N) without any risk of producing affected offspring. The offspring should be tested before breeding to determine if they are carriers or normal.
– Breeding two carriers (N/tns x N/tns) is not recommended due to the possibility of 25% of the offspring being affected.
– Affected animals (tns/tns) should not be used for breeding.
Test Information: This mutation test identifies a 4 base pair deletion in exon 19 of the VPS13B gene.
Further information is available at the Online Mendelian Inheritance in Animals website.