Health Issues:
Written by: Jeff Vidt, DVM

The Answer Continued

Way back in 1983 we first started recognizing episodic fevers in Shar-Pei often associated with a swollen, painful hock joint. Later on it was observed that an early-onset kidney failure occurred in many of these dogs as well. I remember many individuals, including myself, remarking that this has to be associated with the wrinkles in some way and now we know it does.

An important article was recently published in March, 2011, entitled “A Novel Unstable Duplication Upstream of HAS2 Predisposes to a Breed-Defining Skin Phenotype and a Periodic Fever Syndrome in Chinese Shar-Pei Dogs”, Mia Olsson et al. It is the product of a consortium of researchers from several countries, working in several laboratories and our own Dr. Linda Tintle. http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1001332

The major points of the article are as follows:

  1. Chromosome 13
  2. HAS2
  3. 16.1 kb duplication
  4. Hyper HA syndrome
  5. Copy number
  6. Alterations in balance between native high molecular weight HA vs. fragmented low molecular weight HA (including oligomers) may result in activation of the innate immune system.
    1. Two pathways lead to increased formation of IL-1β, a pro-inflammatory cytokine.
    2. One pathway involves Toll-like receptors TLR2 and TLR4.
    3. The other pathway involves the NLRP3 inflammasome – a NLRP3 scaffold, ASC adaptor protein and caspase-1 enzyme. This inflammasome is present in the cytoplasm of monocytes, macrophages and mast cells.
  7. It is likely a blood test may be available in the near future to screen Shar-Pei for their CNV number and the meatmouth mutation. Breeders can avoid using those individuals with high CNV numbers in their breeding programs. This test may also be useful in the general Shar-Pei population to pick out those individuals who may be at risk for FSF +/- amyloidosis. A possible blood test is being validated at this time.
  8. A more general conclusion from this paper is the association of degree of wrinkling in American Shar-Pei with the incidence of FSF and amyloidosis. A general guideline would be to only use those individuals with mild to moderate wrinkling in breeding programs and breed away from Hyper HA dogs. It would appear these guidelines are not necessary in the traditional Chinese Shar-Pei.
  9. Lastly, the association of over-expression of HAS2 and autoinflammation most certainly has implications in the periodic fever syndromes in humans many of which are unexplained at this time.

Jeff Vidt, DVM (3/20/11)