Autoimmune Lymphoproliferative Syndrome (ALPS) is a rare, severe disorder that has been described in British Shorthair cats. The disorder is caused by the inability of the body to destroy unneeded T-lymphocytes, which leads to massive accumulation of T-lymphocytes within lymph nodes. Diffuse enlargement of lymph nodes is typically noticed in kittens around six weeks of age. The progression of clinical signs is rapid and affected kittens develop severe abdominal distension, lethargy, and weight loss. Regenerative anemia is also typically present. No effective treatment has been described and affected kittens are typically euthanized for humane reasons before four months of age.

Upon initial observation of clinical signs, affected cats should be closely monitored to assess welfare. As clinical signs are rapidly progressive, affected cats are usually euthanized on welfare grounds by four months of age.

There are many responsibilities to consider when breeding cats. Regardless of test results it is important that your cat is in good general health and that you are in a position to care for the kittens if new responsible owners are not found. For first time or novice breeders, advice can be found at most cat registry websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to be shown. A carrier cat with one copy of the Autoimmune Lymphoproliferative Syndrome mutation can be safely bred with a clear cat with no copies of the Autoimmune Lymphoproliferative Syndrome mutation. About half of the kittens will have one copy (carriers) and half will have no copies of the Autoimmune Lymphoproliferative Syndrome mutation. Kittens in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected kittens. Please note: It is possible that disease signs similar to the ones caused by the Autoimmune Lymphoproliferative Syndrome mutation could develop due to a different genetic or clinical cause.