Reference 10-98 Akita National
Specialty Presentation
July,
1999
From:
Dr. John
Angles
Diplomate ACVIM
Small Animal Clinical Studies
University College Dublin
Re: Akita
MHC study and the “split” debate
Further to several requests and comments received over the last
week, the following may help to clarify some points concerning
the UC-Davis Akita MHC study:
The Akita MHC study was specifically aimed at understanding the
underlying causes for autoimmune disease in the “American”
Akita, and 90% of our samples have come from this source. We
have been involved with the Finnish Akita club with specific
regard to Sebaceous adenitis, and we have a limited number of
“Japanese” type Akita DNA samples. However, the results
reported to date are for the “American” Akita.
A separate study is being developed at present to examine the
origins of the “American” Akita, and I would be very
interested in getting additional samples for the “Japanese”
type of Akita. This is an unrelated study to the Akita MHC
study, and would not only type the MHC alleles, but also
mitochondrial and microsatellite DNA markers. This study is yet
to be started.
The Akita MHC study suggests that the “American” Akita has
limited variability in the MHC class II genes DRB, DQA and DQB.
While other genes involved in the immune response have yet to be
looked at, we view the limited variability in these MHC genes as
an important finding in light of the high prevalence of
autoimmune disease in the “American” Akita (Akita Dog,
Summer 1998; p. 48). Research in other animals suggests that
decreased variability in the MHC places a species at risk for
increased infectious disease, autoimmune disease and cancer.
While I am aware of autoimmune disease occurring in Akitas in
both Europe and Japan, we have no data on the prevalence of
diseases in these populations. Our studies looking at VKH-like
disease and Myasthenia gravis are specifically directed at the
“American” Akita population.
To address the issue of the “American” vs. the
“Japanese” Akita split will require a broad study examining
the differences and similarities in a number of genetic loci.
This type of study would involve examining both phenotypic
differences between the types (anatomical, hematological,
biochemical, etc.), as well as DNA studies. I am more than willing
to answer any specific questions, and hope that some of the
above will help to clarify the results of the Akita MHC study.
Sincerely
Dr. John Angles