New study on the genetics of Shar-Pei Autoinflammatory Disease (SPAID)
Familial Shar-Pei Fever (FSF) is disease as part of the autoinflammatory complex called „SPAID“ (Shar-Pei Autoinflammatory Disease). Clinical signs comprise high fever, inflammation of the ears, joints and skin. Affected dogs frequently show only some of these symptoms. The high fever episodes, similar as seen in human familial Mediterranial fever, are often accompanied by swoolen hooks and/or a swollen mouth. It is assumed that these recurrent fever episodes are cause for secundary amyloidosis (AA-amyloidosis). However, amyloidosis can also be the result of persistent infections, inflammation or neoplastic diseases, which lead to chronic accumulation of malformed protein (amyloid) in the kidney or heart, liver, pancreas, adrenal gland or intestinal submucosa and subsequent damage in the storage locations. In Shar-Pei, it is reported that most of the amyloid can be found in the kidney marrow (medullar interstitium), whereas other dog breed are reported to accumulate amyloid in the cortx of the kidney. Affected dogs show unspecific signs such as anorexia, nausea, lethargia, and weight loss.
The genetic cause of SPAID in Shar-Pei was identified in a resarch project at the former Institute for Animal Breeding and Genetics (nowadays: Institute for Animal Genomics) supported by Shar-Pei breeders and breeding organisations (1. Deutscher Shar Pei Club 1985 e.V., Shar Pei Freunde Deutschland and World of Shar Pei). A totally new finding was made: For the first time, a significant factor and trigger for the disease was found (siehe Metzger et al.). The identified mutation was apparently genetically linked to the locus harbouring a copy number variation, which has been associated with the variation in the degree of wrinkles in Shar-Pei dogs. This resulted in earlier times in mixing up wrinkle- and SPAID-associated genetics.
Currently, the research group is trying to find out more about the functional consequences of the mutation. Human medical research already shows that single mutations can cause severe autoimmune diseases. However, the severity of the symptoms is highly variable based on what we know from patient reports. People with the same disease mutations apparently reveal different clinical manifestations- from minimal symptoms to severe diseases. This is partly due to the involvement of different organ systems affected by inflammatory processes. It can be assumed that it is a similar situation in the disease complex of SPAID in Shar-Pei. So, can we find protective and risk factors involved in SPAID? The answer for this question can be probably found in the genome of the dog, besides other factors like environmental factors of food related effects.
Update (01/25): The collection of samples was completed (phase 1). At the moment, labwork is done to further process the samples (phase 2). After this step, data will be analyzed (phase 3) and transcriptome profiles willl be prepared for the participants of this study (phase 4). Updates on phase 2 will be publised here.
