Trapped Neutrophil Syndrome (TNS) is a hereditary disease in which the bone marrow produces neutrophils (white cells) but is unable to effectively release them into the bloodstream. Affected puppies have an impaired immune system and will eventually die from infections they cannot fight. The mutation responsible for TNS has been found in Border Collies in English working dogs, in show dogs that had originated in Australia and New Zealand, and in unrelated Australian working dogs. This indicates that the gene is widespread and probably as old as the breed itself. TNS was identified by Jeremy Shearman in the laboratory of Dr. Alan Wilton of the School of Biotechnology and Biomolecular Sciences, University of New South Wales. There is no cure, but a DNA test is now available to detect carriers as well as affected dogs.